Conunonwealth of Massachusetts United States

Department of Environmental Protection Environmental Protection Agency

Western Regional Office New England Region

436 Dwight Street J F Kennedy Federal Building Springfield Massachusetts 01103 Boston Massachusetts 02203 (413) 784-1100 (617) 565-3420

August 13 1997

Jane Magee General Electric Company Area Environmental and Facility Operations 100 Woodlawn Avenue Pittsfield Massachusetts 01201

Re DEP 1-0147 Pittsfield EPA Area 6 GEHousatonic River Proposal for Human Health Risk Assessment Final Comments

Dear Ms Magee

The Massachusetts Department of Environmental Protection (DEP) and the United States Environmental Protection Agency (EPA) (the Agencies) have reviewed the following document

Proposal for Human Health Risk Assessment of the Housatonic River (Proposal) February 14 1996 prepared by ChemRisk for the General Electric Company (GE)

The Proposal is required by EPAs RCRA Corrective Action Permits Special Permit Condition A7 and is intended to fulfill the requirements of DEPs and GEs Administrative Consent Order and the Massachusetts Contingency Plan (MCP)

In accordance with the Public Involvement Plan notifications of the Proposal being placed in the public infonnation repositories were sent by GE to the parties on the notification mailing list at the time of the submittal along with notifications of how and to whom to submit comments during the public comment period

The Agencies are hereby issuing their final comments on and conditional approval of the Proposal The Agencies previously issued draft comments on November 19 1996 On December 19 1996 GE submitted its response to the draft comments The Agencies met on March 6 1997 with GE to discuss GEs comments In preparing the attached final comments the Agencies have considered GEs comments as well as comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative

Ms Jane Magee August 13 1997 Page 2

(Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Environmental Engineering)

As discussed with GE the Agencies support focusing the initial risk assessment work on generating a risk-based concentration (ie cleanup goal) for each exposure scenario GE should derive a residential cleanup goal (and submit it to the Agencies for review and approval) before cleanup goals are developed for other exposure scenarios The Agencies anticipate needing a final residential cleanup goal before cleanup goals are needed for other exposure scenarios such as recreational or farming

The Agencies note that since the initial risk assessment work will be focused on generating risk-based concentrations it is not necessary to identify all foreseeable future uses of the Housatonic River floodplain at the time that this initial work is conducted and the results submitted A separate document containing maps which identify future uses of the floodplain could be submitted to the Agencies by GE after the initial risk assessment report has been completed In any case the Agencies expect and require GE to proceed expeditiously to conduct the human health risk assessment in accordance with the proposed Scope of Work as modifled by the enclosed comments The Agencies also require that GE submit to the Agencies for review and approval within 30 days from the date of this letter a proposed schedule for completing specific deliverables required for completion of the risk assessment

If you have any questions regarding these matters please contact J Lyn Cutler at (413) 784-1100 extension 316 or Bryan Olson at (617) 573-5747

Sincerely

( l_~r~h-shyJ Lyn Cutler Bryan Olson

Section Chief Environmental Engineer Special Projects Corrective Action Section Bureau of Waste Site Cleanup Office of Site Remediation and Massachusetts Department of Restoration Environmental Protection US EPA New England Region

Attachment AWl hhrafin1tr

Ms Jane Magee August 13 1997 Page 3

cc Andrew Thomas Jr Esq GEAndrew Silfer GE Richard Gates GE Jane Gardner GE James R Bieke Esq Shea amp GardnerRobert Goldman Blasland Bouck amp LeeHarley Laing EPA New England RegionMatt Hoagland EPA New England RegionDouglas Luckerman Esq EPA New England ORCMary Ballew EPA New EnglandJan Reitsma Undersecretary EOEAMary Holland Regional Director DEP WEROAlan Weinberg Regional Engineer DEP WERORobert Bell Esq DEP OGCRalph Child DEP OGC BostonMargaret Harvey DEP ORSSusan Steenstrup DEP WEROMayor Edward Reilly City of PittsfieldConunissioner of Health PittsfieldPittsfield Conservation CommissionHousatonic River InitiativeState Senator Andrea NuciforoState Representative Daniel E BosleyState Representative Christopher J HodgkinsState Representative Shaun P KelleyState Representative Peter J LarkinPublic Information RepositoriesCharles Fredette Connecticut DEPGary Ginsberg Connecticut DPHRobert Smith Connecticut DEPJohn Looney Esq Conn AGs OfficeRichard Webb middotEsq Conn AGs OfficeBetsy Harper Esq Mass AGs OfficeMatthew Brock Esg Mass AGs OfficeKen Finkelstein PhD NOAAAnton P Giedt Esq NOAA OGCMark Barash Esq US DOlSteve Gold Esq US DOJAddie Fiske Esq US DOJKelmeth Carr PhD US FampWSCarol Rowan West DEP ORSNancy Bettinger DEP ORS

TECHNICAL AND REVIEW COMMENTS of

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY and

MASSACHUSETTS DEPARTMENT of ENVIRONMENTAL PROTECTION

GENERAL ELECTRIC COMPANY Pittsfield Massachusetts

EPA lD MAD002084093 Area 6 MCP Site Number 1-0147

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

Prepared by ChemRisk on behalf of General Electric Company Submitted February 14 1996

INTRODUCTION

The US Environmental Protection Agency New England Region (EPA) and the Massachusetts Department of Environmental Protection (DEP) (the Agencies) have compiled the following list of general and specific comments relating to completeness and technical accuracy and adequacy of the Proposal For Human Health Risk Assessment Of The Housatonic River prepared by ChemRisk on behalf of the General Electric Company (GE) and submitted to the Agencies on February 14 1996 (GEs Risk Assessment Proposal) The Agencies have reviewed the Proposal for Human Health Risk Assessment for completeness and consistency with appropriate EPA and DEP regulation policy and guidance

In preparing these comments the Agencies have considered comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative (Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Enviromnental Engineering) TIle Agencies issued Draft Technical And Review Comments dated November 19 1996 for comment The Agencies received comments on the Draft from GE on December 19 1996 On March 6 1997 the Agencies met with GE to discuss GEs comments The Agencies have considered GEs comments and discussions with GE in preparing these revised draft comments

There are two general themes that are common to many of the Agencies comments First many of the Agencies comments address areas of GEs Risk Assessment Proposal that are not consistent with appropriate EPA and DEP regulation policY and guidance Second the Agencies have commented on exposure assumptions proposed by GE that do not adequately characterize (l) the receptor sub population whose activities (described by the frequency and duration of their actions) represent a full and unrestricted use of the site and (2) the Reasonable Maximum Exposure (RME)

The Agencies comments are divided into two major sections General Comments and Specific Comments Specific comments are organized into sections corresponding to the sections in GEs Risk Assessment Proposal The Agencies note that several comments appear in more than one section of this attachment The Agencies have repeated a comment each time the issue appeared in

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GEs Proposal document Each comment that is repeated refers to the section in which the comment first appeared

Attachment A to these comments contains a list of relevant EPA and DEP policy and guidance The Agencies will evaluate and approve or disapprove GEs Human Health Risk Assessment Report in accordance with and based on EPA and DEP policy and guidance listed in Attachment A The Agencies recognize that many of the documents listed in Attachment A have already been consulted by Chern Risk in preparing the Risk Assessment Proposal

Attachment B to these comments contains the general EPA format and content recommendations for Human Health Risk Assessment Reports GE should review these recommendations and ensure that its Human Health Risk Assessment Report contains the appropriate information specified therein to the extent consistent with the comments set forth below and the revised Human Health Risk Assessment Proposal as approved by the Agencies

A GENERAL COMMENTS

I In Section 13 GE proposes to evaluate potential risks to human health iteratively for each exposure scenario in order to focus the assessment on areas where risks to human health are most likely to be present GE proposes to first evaluate the river and floodplain reach with the highest concentrations of Chemicals of Potential Concern (COPC) (ie GE facility to Woods Pond Dam) As proposed by GE if this evaluation shows no significant risks for a given scenario or if it shows a clear pattern of decline to acceptable risks by the downstream boundary of the reach then additional iterations of that scenario for further reaches downstream of Woods Pond will not be performed

TIle Agencies support the objective of streamlining the risk assessment by eliminating calculations that will not provide useful information Toward that end the Agencies have agreed to focus the risk assessment on calculating risk-based concentrations (ie cleanup goals) for each exposure scenario and pathway Below such risk-based concentrations exposure would not pose a significant risk TIlUS in lieu of numerous separate risk calculations the risk assessment report should tabulate exposure point concentration (EPC) estimates for each area to which an exposure scenario applies (for the areas where sampling data are available) At a minimum for each exposure point the upper 95 percent confidence limit of the mean should be calculated as the EPC (see comment 34) The average concentration detected should also be presented To determine whether a significant risk of harm exists at any location the EPe should simply be compared with the risk-based concentration for the relevant exposure scenario(s) For each exposure area the risk assessment report should indicate whether the EPe exceeds the relevant risk-based concentration

This approach would have a number of advantages

Calculating risk-based concentrations for each scenario eliminates the need for repetitive calculations Only the EPe for each location would be reported location-specific risk estimates would not be needed Further separate risk calculations for all exposure scenarios that are foreseeable at each location would be ullllecessary

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The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner It will not be necessary to selectively focus on the locations likely to pose the highest risk All locations that could pose a significant risk would be identified

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions It is not necessary to establish a priori which combination of exposures apply at each location

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations EPC estimates would be presented for all locations of potential concern

In addition to calculating risk-based concentrations GE should also include a forward calculation (risk estimate) for each exposure scenario TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete For the risk estimates GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario Using a selected EPC (rather than calculating it using site data) is preferable becausemiddot it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC

2 Based on the discussion in Section 7 of the Risk Assessment Proposal it appears that GE intends to calculate cumulative risks separately for each exposure scenario (ie GE intends to assume that exposure scenarios are mutually exclusive) The Agencies believe this is an acceptable approach for the risk assessment particularly if the focus is on risk-based concentrations However the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example canoeing and picnicking residential exposures and consumption of fish)

3 As part of the uncertainty section of the risk assessment GE must address the potential for PCBs to act as endocrine disruptors GE should consider the discussion provided in Attachment C which reflects Agency views on potential endocrine disrupting effects

4 GE states that it has proposed reasonable and realistic values for exposure parameters to be used in the risk assessment For each exposure scenario the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the full use assumptions specified in the Massachusetts Contingency Plan (MCP) TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE In the

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detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

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middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

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The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

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12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

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Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

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SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

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SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

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SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

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ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

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Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

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ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

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bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Ms Jane Magee August 13 1997 Page 2

(Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Environmental Engineering)

As discussed with GE the Agencies support focusing the initial risk assessment work on generating a risk-based concentration (ie cleanup goal) for each exposure scenario GE should derive a residential cleanup goal (and submit it to the Agencies for review and approval) before cleanup goals are developed for other exposure scenarios The Agencies anticipate needing a final residential cleanup goal before cleanup goals are needed for other exposure scenarios such as recreational or farming

The Agencies note that since the initial risk assessment work will be focused on generating risk-based concentrations it is not necessary to identify all foreseeable future uses of the Housatonic River floodplain at the time that this initial work is conducted and the results submitted A separate document containing maps which identify future uses of the floodplain could be submitted to the Agencies by GE after the initial risk assessment report has been completed In any case the Agencies expect and require GE to proceed expeditiously to conduct the human health risk assessment in accordance with the proposed Scope of Work as modifled by the enclosed comments The Agencies also require that GE submit to the Agencies for review and approval within 30 days from the date of this letter a proposed schedule for completing specific deliverables required for completion of the risk assessment

If you have any questions regarding these matters please contact J Lyn Cutler at (413) 784-1100 extension 316 or Bryan Olson at (617) 573-5747

Sincerely

( l_~r~h-shyJ Lyn Cutler Bryan Olson

Section Chief Environmental Engineer Special Projects Corrective Action Section Bureau of Waste Site Cleanup Office of Site Remediation and Massachusetts Department of Restoration Environmental Protection US EPA New England Region

Attachment AWl hhrafin1tr

Ms Jane Magee August 13 1997 Page 3

cc Andrew Thomas Jr Esq GEAndrew Silfer GE Richard Gates GE Jane Gardner GE James R Bieke Esq Shea amp GardnerRobert Goldman Blasland Bouck amp LeeHarley Laing EPA New England RegionMatt Hoagland EPA New England RegionDouglas Luckerman Esq EPA New England ORCMary Ballew EPA New EnglandJan Reitsma Undersecretary EOEAMary Holland Regional Director DEP WEROAlan Weinberg Regional Engineer DEP WERORobert Bell Esq DEP OGCRalph Child DEP OGC BostonMargaret Harvey DEP ORSSusan Steenstrup DEP WEROMayor Edward Reilly City of PittsfieldConunissioner of Health PittsfieldPittsfield Conservation CommissionHousatonic River InitiativeState Senator Andrea NuciforoState Representative Daniel E BosleyState Representative Christopher J HodgkinsState Representative Shaun P KelleyState Representative Peter J LarkinPublic Information RepositoriesCharles Fredette Connecticut DEPGary Ginsberg Connecticut DPHRobert Smith Connecticut DEPJohn Looney Esq Conn AGs OfficeRichard Webb middotEsq Conn AGs OfficeBetsy Harper Esq Mass AGs OfficeMatthew Brock Esg Mass AGs OfficeKen Finkelstein PhD NOAAAnton P Giedt Esq NOAA OGCMark Barash Esq US DOlSteve Gold Esq US DOJAddie Fiske Esq US DOJKelmeth Carr PhD US FampWSCarol Rowan West DEP ORSNancy Bettinger DEP ORS

TECHNICAL AND REVIEW COMMENTS of

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY and

MASSACHUSETTS DEPARTMENT of ENVIRONMENTAL PROTECTION

GENERAL ELECTRIC COMPANY Pittsfield Massachusetts

EPA lD MAD002084093 Area 6 MCP Site Number 1-0147

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

Prepared by ChemRisk on behalf of General Electric Company Submitted February 14 1996

INTRODUCTION

The US Environmental Protection Agency New England Region (EPA) and the Massachusetts Department of Environmental Protection (DEP) (the Agencies) have compiled the following list of general and specific comments relating to completeness and technical accuracy and adequacy of the Proposal For Human Health Risk Assessment Of The Housatonic River prepared by ChemRisk on behalf of the General Electric Company (GE) and submitted to the Agencies on February 14 1996 (GEs Risk Assessment Proposal) The Agencies have reviewed the Proposal for Human Health Risk Assessment for completeness and consistency with appropriate EPA and DEP regulation policy and guidance

In preparing these comments the Agencies have considered comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative (Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Enviromnental Engineering) TIle Agencies issued Draft Technical And Review Comments dated November 19 1996 for comment The Agencies received comments on the Draft from GE on December 19 1996 On March 6 1997 the Agencies met with GE to discuss GEs comments The Agencies have considered GEs comments and discussions with GE in preparing these revised draft comments

There are two general themes that are common to many of the Agencies comments First many of the Agencies comments address areas of GEs Risk Assessment Proposal that are not consistent with appropriate EPA and DEP regulation policY and guidance Second the Agencies have commented on exposure assumptions proposed by GE that do not adequately characterize (l) the receptor sub population whose activities (described by the frequency and duration of their actions) represent a full and unrestricted use of the site and (2) the Reasonable Maximum Exposure (RME)

The Agencies comments are divided into two major sections General Comments and Specific Comments Specific comments are organized into sections corresponding to the sections in GEs Risk Assessment Proposal The Agencies note that several comments appear in more than one section of this attachment The Agencies have repeated a comment each time the issue appeared in

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GEs Proposal document Each comment that is repeated refers to the section in which the comment first appeared

Attachment A to these comments contains a list of relevant EPA and DEP policy and guidance The Agencies will evaluate and approve or disapprove GEs Human Health Risk Assessment Report in accordance with and based on EPA and DEP policy and guidance listed in Attachment A The Agencies recognize that many of the documents listed in Attachment A have already been consulted by Chern Risk in preparing the Risk Assessment Proposal

Attachment B to these comments contains the general EPA format and content recommendations for Human Health Risk Assessment Reports GE should review these recommendations and ensure that its Human Health Risk Assessment Report contains the appropriate information specified therein to the extent consistent with the comments set forth below and the revised Human Health Risk Assessment Proposal as approved by the Agencies

A GENERAL COMMENTS

I In Section 13 GE proposes to evaluate potential risks to human health iteratively for each exposure scenario in order to focus the assessment on areas where risks to human health are most likely to be present GE proposes to first evaluate the river and floodplain reach with the highest concentrations of Chemicals of Potential Concern (COPC) (ie GE facility to Woods Pond Dam) As proposed by GE if this evaluation shows no significant risks for a given scenario or if it shows a clear pattern of decline to acceptable risks by the downstream boundary of the reach then additional iterations of that scenario for further reaches downstream of Woods Pond will not be performed

TIle Agencies support the objective of streamlining the risk assessment by eliminating calculations that will not provide useful information Toward that end the Agencies have agreed to focus the risk assessment on calculating risk-based concentrations (ie cleanup goals) for each exposure scenario and pathway Below such risk-based concentrations exposure would not pose a significant risk TIlUS in lieu of numerous separate risk calculations the risk assessment report should tabulate exposure point concentration (EPC) estimates for each area to which an exposure scenario applies (for the areas where sampling data are available) At a minimum for each exposure point the upper 95 percent confidence limit of the mean should be calculated as the EPC (see comment 34) The average concentration detected should also be presented To determine whether a significant risk of harm exists at any location the EPe should simply be compared with the risk-based concentration for the relevant exposure scenario(s) For each exposure area the risk assessment report should indicate whether the EPe exceeds the relevant risk-based concentration

This approach would have a number of advantages

Calculating risk-based concentrations for each scenario eliminates the need for repetitive calculations Only the EPe for each location would be reported location-specific risk estimates would not be needed Further separate risk calculations for all exposure scenarios that are foreseeable at each location would be ullllecessary

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The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner It will not be necessary to selectively focus on the locations likely to pose the highest risk All locations that could pose a significant risk would be identified

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions It is not necessary to establish a priori which combination of exposures apply at each location

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations EPC estimates would be presented for all locations of potential concern

In addition to calculating risk-based concentrations GE should also include a forward calculation (risk estimate) for each exposure scenario TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete For the risk estimates GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario Using a selected EPC (rather than calculating it using site data) is preferable becausemiddot it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC

2 Based on the discussion in Section 7 of the Risk Assessment Proposal it appears that GE intends to calculate cumulative risks separately for each exposure scenario (ie GE intends to assume that exposure scenarios are mutually exclusive) The Agencies believe this is an acceptable approach for the risk assessment particularly if the focus is on risk-based concentrations However the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example canoeing and picnicking residential exposures and consumption of fish)

3 As part of the uncertainty section of the risk assessment GE must address the potential for PCBs to act as endocrine disruptors GE should consider the discussion provided in Attachment C which reflects Agency views on potential endocrine disrupting effects

4 GE states that it has proposed reasonable and realistic values for exposure parameters to be used in the risk assessment For each exposure scenario the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the full use assumptions specified in the Massachusetts Contingency Plan (MCP) TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE In the

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detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Ms Jane Magee August 13 1997 Page 3

cc Andrew Thomas Jr Esq GEAndrew Silfer GE Richard Gates GE Jane Gardner GE James R Bieke Esq Shea amp GardnerRobert Goldman Blasland Bouck amp LeeHarley Laing EPA New England RegionMatt Hoagland EPA New England RegionDouglas Luckerman Esq EPA New England ORCMary Ballew EPA New EnglandJan Reitsma Undersecretary EOEAMary Holland Regional Director DEP WEROAlan Weinberg Regional Engineer DEP WERORobert Bell Esq DEP OGCRalph Child DEP OGC BostonMargaret Harvey DEP ORSSusan Steenstrup DEP WEROMayor Edward Reilly City of PittsfieldConunissioner of Health PittsfieldPittsfield Conservation CommissionHousatonic River InitiativeState Senator Andrea NuciforoState Representative Daniel E BosleyState Representative Christopher J HodgkinsState Representative Shaun P KelleyState Representative Peter J LarkinPublic Information RepositoriesCharles Fredette Connecticut DEPGary Ginsberg Connecticut DPHRobert Smith Connecticut DEPJohn Looney Esq Conn AGs OfficeRichard Webb middotEsq Conn AGs OfficeBetsy Harper Esq Mass AGs OfficeMatthew Brock Esg Mass AGs OfficeKen Finkelstein PhD NOAAAnton P Giedt Esq NOAA OGCMark Barash Esq US DOlSteve Gold Esq US DOJAddie Fiske Esq US DOJKelmeth Carr PhD US FampWSCarol Rowan West DEP ORSNancy Bettinger DEP ORS

TECHNICAL AND REVIEW COMMENTS of

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY and

MASSACHUSETTS DEPARTMENT of ENVIRONMENTAL PROTECTION

GENERAL ELECTRIC COMPANY Pittsfield Massachusetts

EPA lD MAD002084093 Area 6 MCP Site Number 1-0147

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

Prepared by ChemRisk on behalf of General Electric Company Submitted February 14 1996

INTRODUCTION

The US Environmental Protection Agency New England Region (EPA) and the Massachusetts Department of Environmental Protection (DEP) (the Agencies) have compiled the following list of general and specific comments relating to completeness and technical accuracy and adequacy of the Proposal For Human Health Risk Assessment Of The Housatonic River prepared by ChemRisk on behalf of the General Electric Company (GE) and submitted to the Agencies on February 14 1996 (GEs Risk Assessment Proposal) The Agencies have reviewed the Proposal for Human Health Risk Assessment for completeness and consistency with appropriate EPA and DEP regulation policy and guidance

In preparing these comments the Agencies have considered comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative (Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Enviromnental Engineering) TIle Agencies issued Draft Technical And Review Comments dated November 19 1996 for comment The Agencies received comments on the Draft from GE on December 19 1996 On March 6 1997 the Agencies met with GE to discuss GEs comments The Agencies have considered GEs comments and discussions with GE in preparing these revised draft comments

There are two general themes that are common to many of the Agencies comments First many of the Agencies comments address areas of GEs Risk Assessment Proposal that are not consistent with appropriate EPA and DEP regulation policY and guidance Second the Agencies have commented on exposure assumptions proposed by GE that do not adequately characterize (l) the receptor sub population whose activities (described by the frequency and duration of their actions) represent a full and unrestricted use of the site and (2) the Reasonable Maximum Exposure (RME)

The Agencies comments are divided into two major sections General Comments and Specific Comments Specific comments are organized into sections corresponding to the sections in GEs Risk Assessment Proposal The Agencies note that several comments appear in more than one section of this attachment The Agencies have repeated a comment each time the issue appeared in

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GEs Proposal document Each comment that is repeated refers to the section in which the comment first appeared

Attachment A to these comments contains a list of relevant EPA and DEP policy and guidance The Agencies will evaluate and approve or disapprove GEs Human Health Risk Assessment Report in accordance with and based on EPA and DEP policy and guidance listed in Attachment A The Agencies recognize that many of the documents listed in Attachment A have already been consulted by Chern Risk in preparing the Risk Assessment Proposal

Attachment B to these comments contains the general EPA format and content recommendations for Human Health Risk Assessment Reports GE should review these recommendations and ensure that its Human Health Risk Assessment Report contains the appropriate information specified therein to the extent consistent with the comments set forth below and the revised Human Health Risk Assessment Proposal as approved by the Agencies

A GENERAL COMMENTS

I In Section 13 GE proposes to evaluate potential risks to human health iteratively for each exposure scenario in order to focus the assessment on areas where risks to human health are most likely to be present GE proposes to first evaluate the river and floodplain reach with the highest concentrations of Chemicals of Potential Concern (COPC) (ie GE facility to Woods Pond Dam) As proposed by GE if this evaluation shows no significant risks for a given scenario or if it shows a clear pattern of decline to acceptable risks by the downstream boundary of the reach then additional iterations of that scenario for further reaches downstream of Woods Pond will not be performed

TIle Agencies support the objective of streamlining the risk assessment by eliminating calculations that will not provide useful information Toward that end the Agencies have agreed to focus the risk assessment on calculating risk-based concentrations (ie cleanup goals) for each exposure scenario and pathway Below such risk-based concentrations exposure would not pose a significant risk TIlUS in lieu of numerous separate risk calculations the risk assessment report should tabulate exposure point concentration (EPC) estimates for each area to which an exposure scenario applies (for the areas where sampling data are available) At a minimum for each exposure point the upper 95 percent confidence limit of the mean should be calculated as the EPC (see comment 34) The average concentration detected should also be presented To determine whether a significant risk of harm exists at any location the EPe should simply be compared with the risk-based concentration for the relevant exposure scenario(s) For each exposure area the risk assessment report should indicate whether the EPe exceeds the relevant risk-based concentration

This approach would have a number of advantages

Calculating risk-based concentrations for each scenario eliminates the need for repetitive calculations Only the EPe for each location would be reported location-specific risk estimates would not be needed Further separate risk calculations for all exposure scenarios that are foreseeable at each location would be ullllecessary

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The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner It will not be necessary to selectively focus on the locations likely to pose the highest risk All locations that could pose a significant risk would be identified

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions It is not necessary to establish a priori which combination of exposures apply at each location

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations EPC estimates would be presented for all locations of potential concern

In addition to calculating risk-based concentrations GE should also include a forward calculation (risk estimate) for each exposure scenario TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete For the risk estimates GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario Using a selected EPC (rather than calculating it using site data) is preferable becausemiddot it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC

2 Based on the discussion in Section 7 of the Risk Assessment Proposal it appears that GE intends to calculate cumulative risks separately for each exposure scenario (ie GE intends to assume that exposure scenarios are mutually exclusive) The Agencies believe this is an acceptable approach for the risk assessment particularly if the focus is on risk-based concentrations However the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example canoeing and picnicking residential exposures and consumption of fish)

3 As part of the uncertainty section of the risk assessment GE must address the potential for PCBs to act as endocrine disruptors GE should consider the discussion provided in Attachment C which reflects Agency views on potential endocrine disrupting effects

4 GE states that it has proposed reasonable and realistic values for exposure parameters to be used in the risk assessment For each exposure scenario the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the full use assumptions specified in the Massachusetts Contingency Plan (MCP) TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE In the

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detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

TECHNICAL AND REVIEW COMMENTS of

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY and

MASSACHUSETTS DEPARTMENT of ENVIRONMENTAL PROTECTION

GENERAL ELECTRIC COMPANY Pittsfield Massachusetts

EPA lD MAD002084093 Area 6 MCP Site Number 1-0147

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

Prepared by ChemRisk on behalf of General Electric Company Submitted February 14 1996

INTRODUCTION

The US Environmental Protection Agency New England Region (EPA) and the Massachusetts Department of Environmental Protection (DEP) (the Agencies) have compiled the following list of general and specific comments relating to completeness and technical accuracy and adequacy of the Proposal For Human Health Risk Assessment Of The Housatonic River prepared by ChemRisk on behalf of the General Electric Company (GE) and submitted to the Agencies on February 14 1996 (GEs Risk Assessment Proposal) The Agencies have reviewed the Proposal for Human Health Risk Assessment for completeness and consistency with appropriate EPA and DEP regulation policy and guidance

In preparing these comments the Agencies have considered comments submitted by the Connecticut Department of Public Health and the Housatonic River Initiative (Housatonic River Initiative comments were prepared by Anne Marie Desmarais of the Tufts University Department of Civil and Enviromnental Engineering) TIle Agencies issued Draft Technical And Review Comments dated November 19 1996 for comment The Agencies received comments on the Draft from GE on December 19 1996 On March 6 1997 the Agencies met with GE to discuss GEs comments The Agencies have considered GEs comments and discussions with GE in preparing these revised draft comments

There are two general themes that are common to many of the Agencies comments First many of the Agencies comments address areas of GEs Risk Assessment Proposal that are not consistent with appropriate EPA and DEP regulation policY and guidance Second the Agencies have commented on exposure assumptions proposed by GE that do not adequately characterize (l) the receptor sub population whose activities (described by the frequency and duration of their actions) represent a full and unrestricted use of the site and (2) the Reasonable Maximum Exposure (RME)

The Agencies comments are divided into two major sections General Comments and Specific Comments Specific comments are organized into sections corresponding to the sections in GEs Risk Assessment Proposal The Agencies note that several comments appear in more than one section of this attachment The Agencies have repeated a comment each time the issue appeared in

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GEs Proposal document Each comment that is repeated refers to the section in which the comment first appeared

Attachment A to these comments contains a list of relevant EPA and DEP policy and guidance The Agencies will evaluate and approve or disapprove GEs Human Health Risk Assessment Report in accordance with and based on EPA and DEP policy and guidance listed in Attachment A The Agencies recognize that many of the documents listed in Attachment A have already been consulted by Chern Risk in preparing the Risk Assessment Proposal

Attachment B to these comments contains the general EPA format and content recommendations for Human Health Risk Assessment Reports GE should review these recommendations and ensure that its Human Health Risk Assessment Report contains the appropriate information specified therein to the extent consistent with the comments set forth below and the revised Human Health Risk Assessment Proposal as approved by the Agencies

A GENERAL COMMENTS

I In Section 13 GE proposes to evaluate potential risks to human health iteratively for each exposure scenario in order to focus the assessment on areas where risks to human health are most likely to be present GE proposes to first evaluate the river and floodplain reach with the highest concentrations of Chemicals of Potential Concern (COPC) (ie GE facility to Woods Pond Dam) As proposed by GE if this evaluation shows no significant risks for a given scenario or if it shows a clear pattern of decline to acceptable risks by the downstream boundary of the reach then additional iterations of that scenario for further reaches downstream of Woods Pond will not be performed

TIle Agencies support the objective of streamlining the risk assessment by eliminating calculations that will not provide useful information Toward that end the Agencies have agreed to focus the risk assessment on calculating risk-based concentrations (ie cleanup goals) for each exposure scenario and pathway Below such risk-based concentrations exposure would not pose a significant risk TIlUS in lieu of numerous separate risk calculations the risk assessment report should tabulate exposure point concentration (EPC) estimates for each area to which an exposure scenario applies (for the areas where sampling data are available) At a minimum for each exposure point the upper 95 percent confidence limit of the mean should be calculated as the EPC (see comment 34) The average concentration detected should also be presented To determine whether a significant risk of harm exists at any location the EPe should simply be compared with the risk-based concentration for the relevant exposure scenario(s) For each exposure area the risk assessment report should indicate whether the EPe exceeds the relevant risk-based concentration

This approach would have a number of advantages

Calculating risk-based concentrations for each scenario eliminates the need for repetitive calculations Only the EPe for each location would be reported location-specific risk estimates would not be needed Further separate risk calculations for all exposure scenarios that are foreseeable at each location would be ullllecessary

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The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner It will not be necessary to selectively focus on the locations likely to pose the highest risk All locations that could pose a significant risk would be identified

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions It is not necessary to establish a priori which combination of exposures apply at each location

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations EPC estimates would be presented for all locations of potential concern

In addition to calculating risk-based concentrations GE should also include a forward calculation (risk estimate) for each exposure scenario TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete For the risk estimates GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario Using a selected EPC (rather than calculating it using site data) is preferable becausemiddot it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC

2 Based on the discussion in Section 7 of the Risk Assessment Proposal it appears that GE intends to calculate cumulative risks separately for each exposure scenario (ie GE intends to assume that exposure scenarios are mutually exclusive) The Agencies believe this is an acceptable approach for the risk assessment particularly if the focus is on risk-based concentrations However the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example canoeing and picnicking residential exposures and consumption of fish)

3 As part of the uncertainty section of the risk assessment GE must address the potential for PCBs to act as endocrine disruptors GE should consider the discussion provided in Attachment C which reflects Agency views on potential endocrine disrupting effects

4 GE states that it has proposed reasonable and realistic values for exposure parameters to be used in the risk assessment For each exposure scenario the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the full use assumptions specified in the Massachusetts Contingency Plan (MCP) TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE In the

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detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

GEs Proposal document Each comment that is repeated refers to the section in which the comment first appeared

Attachment A to these comments contains a list of relevant EPA and DEP policy and guidance The Agencies will evaluate and approve or disapprove GEs Human Health Risk Assessment Report in accordance with and based on EPA and DEP policy and guidance listed in Attachment A The Agencies recognize that many of the documents listed in Attachment A have already been consulted by Chern Risk in preparing the Risk Assessment Proposal

Attachment B to these comments contains the general EPA format and content recommendations for Human Health Risk Assessment Reports GE should review these recommendations and ensure that its Human Health Risk Assessment Report contains the appropriate information specified therein to the extent consistent with the comments set forth below and the revised Human Health Risk Assessment Proposal as approved by the Agencies

A GENERAL COMMENTS

I In Section 13 GE proposes to evaluate potential risks to human health iteratively for each exposure scenario in order to focus the assessment on areas where risks to human health are most likely to be present GE proposes to first evaluate the river and floodplain reach with the highest concentrations of Chemicals of Potential Concern (COPC) (ie GE facility to Woods Pond Dam) As proposed by GE if this evaluation shows no significant risks for a given scenario or if it shows a clear pattern of decline to acceptable risks by the downstream boundary of the reach then additional iterations of that scenario for further reaches downstream of Woods Pond will not be performed

TIle Agencies support the objective of streamlining the risk assessment by eliminating calculations that will not provide useful information Toward that end the Agencies have agreed to focus the risk assessment on calculating risk-based concentrations (ie cleanup goals) for each exposure scenario and pathway Below such risk-based concentrations exposure would not pose a significant risk TIlUS in lieu of numerous separate risk calculations the risk assessment report should tabulate exposure point concentration (EPC) estimates for each area to which an exposure scenario applies (for the areas where sampling data are available) At a minimum for each exposure point the upper 95 percent confidence limit of the mean should be calculated as the EPC (see comment 34) The average concentration detected should also be presented To determine whether a significant risk of harm exists at any location the EPe should simply be compared with the risk-based concentration for the relevant exposure scenario(s) For each exposure area the risk assessment report should indicate whether the EPe exceeds the relevant risk-based concentration

This approach would have a number of advantages

Calculating risk-based concentrations for each scenario eliminates the need for repetitive calculations Only the EPe for each location would be reported location-specific risk estimates would not be needed Further separate risk calculations for all exposure scenarios that are foreseeable at each location would be ullllecessary

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The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner It will not be necessary to selectively focus on the locations likely to pose the highest risk All locations that could pose a significant risk would be identified

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions It is not necessary to establish a priori which combination of exposures apply at each location

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations EPC estimates would be presented for all locations of potential concern

In addition to calculating risk-based concentrations GE should also include a forward calculation (risk estimate) for each exposure scenario TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete For the risk estimates GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario Using a selected EPC (rather than calculating it using site data) is preferable becausemiddot it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC

2 Based on the discussion in Section 7 of the Risk Assessment Proposal it appears that GE intends to calculate cumulative risks separately for each exposure scenario (ie GE intends to assume that exposure scenarios are mutually exclusive) The Agencies believe this is an acceptable approach for the risk assessment particularly if the focus is on risk-based concentrations However the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example canoeing and picnicking residential exposures and consumption of fish)

3 As part of the uncertainty section of the risk assessment GE must address the potential for PCBs to act as endocrine disruptors GE should consider the discussion provided in Attachment C which reflects Agency views on potential endocrine disrupting effects

4 GE states that it has proposed reasonable and realistic values for exposure parameters to be used in the risk assessment For each exposure scenario the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the full use assumptions specified in the Massachusetts Contingency Plan (MCP) TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE In the

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detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

The comparison of risk-based concentrations to measured exposure point concentrations facilitates incorporation of additional data as it becomes available

Using EPC estimates as indicators of risk would enable the investigators to document risk at a large number of exposure points in a concise manner It will not be necessary to selectively focus on the locations likely to pose the highest risk All locations that could pose a significant risk would be identified

This approach gives project managers the flexibility of accounting for cumulative exposures as appropriate for each location in risk management decisions It is not necessary to establish a priori which combination of exposures apply at each location

Adoption of the risk-based concentration approach would eliminate the need to pare down the assessment document by focusing only on a small subset of locations EPC estimates would be presented for all locations of potential concern

In addition to calculating risk-based concentrations GE should also include a forward calculation (risk estimate) for each exposure scenario TIle purpose of presenting risk estimates in addition to risk-based concentrations is for illustrative purposes only and to make the risk assessment more clear and complete For the risk estimates GE should select an EPC that is likely to be in the range of what a cleanup value would be for a given scenario Using a selected EPC (rather than calculating it using site data) is preferable becausemiddot it avoids the need for discussions between GE and the Agencies about which properties should be used as the basis for the EPC

2 Based on the discussion in Section 7 of the Risk Assessment Proposal it appears that GE intends to calculate cumulative risks separately for each exposure scenario (ie GE intends to assume that exposure scenarios are mutually exclusive) The Agencies believe this is an acceptable approach for the risk assessment particularly if the focus is on risk-based concentrations However the Agencies note that risk management decisions may be made based on plausible combinations of exposure scenarios (for example canoeing and picnicking residential exposures and consumption of fish)

3 As part of the uncertainty section of the risk assessment GE must address the potential for PCBs to act as endocrine disruptors GE should consider the discussion provided in Attachment C which reflects Agency views on potential endocrine disrupting effects

4 GE states that it has proposed reasonable and realistic values for exposure parameters to be used in the risk assessment For each exposure scenario the Agencies favor the development of one risk estimate (or risk-based concentration) that is consistent with both the EPA-defined Reasonable Maximum Exposure (RME) or High End Exposure (HEE) and the full use assumptions specified in the Massachusetts Contingency Plan (MCP) TIle Agencies also recommend the development of a central tendency risk estimate for each exposure scenario to meet EPA requirements and to provide a point of reference indicative of the uncertainty and variability inherent in exposure and risk estimates

RME is defined as the highest exposure that could reasonably be expected to occur for a given exposure pathway at a site HEE is defined as a plausible estimate of the individual exposure for those persons at the upper end of an exposure distribution Some of the exposure assumptions proposed by GE will not adequately characterize the RME or HEE In the

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detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

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ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

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ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

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bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs rusk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One rusk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

The MCP states The selection of site-specific exposure frequency and exposure duration should be representative of the full extent of site activities consistent with the identified Site Use Examples of exposure variables for which full use values are likely to differ siguificantly from central tendency values include frequency and duration of residential and recreational exposures and fish consumption rates

5 For purposes of tile MCP reasonably foreseeable uses includes any possible activity or use that could occur in the future to the extent that such activity or use could result in exposures to Human or Environmental Receptors that are greater than tile exposures associated with current Site Activities and Uses (310 CMR 400923(3raquo

B SPECIFIC COMMENTS

Section 20 Site Characterization Current Uses ofFloodplain

1 There are patterns of current land use that the Risk Assessment Proposal has omitted or has misidentified Such land usesactivities are identified below and should be addressed by GE in the Risk Assessment

Additional recreational uses of Canoe Meadows that frequently take place and should be considered in the risk assessment are picnicking and bird watchingwildlife watching TIlese activities may occur with greater frequency and more intense exposure than the other recreational uses for Canoe Meadows that are listed in the rusk Assessment Proposal For example retired persons may visit Canoe Meadows several times per week Young children also may visit the area frequently as palt of school field trips and camp groups

On page 2-9 GE should describe what is meant by other recreational activities in the waterlI

The discussion of current uses of the floodplain has omitted the stretch of the river from the northern Pomeroy Avenue bridge just upstream of the confluence of the East and West Branches to ilie southern Pomeroy Avenue Bridge just upstream of Holmes Road The Proposal should describe current uses of the floodplain in this stretch of the river

Reasonably Foreseeable Uses ofFloodplain

2 On page 2-12 the Proposal states that the abundance of alternative recreational opportunities in and around Pittsfield should serve to limit the growth of recreational use of the Housatonic ruver to a moderate level This statement is not necessarily true for the following reasons

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TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

TIle Housatonic River is the largest watenvay in the area is extraordinarily scenic and offers a greater diversity of recreational activities than any other single recreational resource

After remediation of the Housatonic River occurs there will likely be increased interest in and use of the River for recreational purposes

Many of the state parks identified in the Proposal are much less accessible than the Housatonic River and do not provide the same recreational opportunities as are provided by the Housatonic River

It is inappropriate to base the exposure assessment on arbitrary and generalized assumptions about recreational preferences and values of the local population

3 Potential future development of the floodplain cannot be eliminated as a possible future use based solely on the Pittsfield Comprehensive Development Plan

4 On page 2-14 the Risk Assessment Proposal states that because of the local state and federal restrictions that apply to development of the floodplain and the costs associated with meeting zoning and conservation commission requirements new construction (if any) will likely be limited to additions or renovations despite widespread designation of floodplain areas as residential It is not necessarily true that new construction will be restricted in the floodplain Construction may still take place in the floodplain if compensatory flood storage can be found In addition in the town zoning laws described in the Proposal new construction can take place if the property owner is willing to forego having a basement or is willing to floodproof the structure Also zoning reqnirements may be amended The Agencies do not agree that local state and federal restrictions will necessarily preclude future residential development in the floodplain Reasonably foreseeable future uses of the floodplain should be considered residential except in areas where there is a clear limitation on residential nses

GE should identifY and map areas where a foreseeable use could result in greater exposure and risk than current use including areas that are not currently residential but where residential use is foreseeable GE should conduct this mapping exercise in cooperation with Agency Project Managers who will consider on a case-by-case basis tlle extent to which factors may preclude specific activities and uses

Section 40 Hazard Identification

41 Selection of Media of Concern

5 GE has determined that exposure to groundwater is not a concern in the Housatonic River and floodplain addressed by this Human Health Risk Assessment Proposal based on investigations which show a lack of influence on groundwater from contaminated soils overlying groundwater and a lack of influence on groundwater from contaminated water and sediment in the Housatonic River and Woods Pond

Based on groundwater categorization GE has concluded that groundwater would not be classified as GW-1 (potential drinking water source) in the stretch of River upstream of New Lenox Road For the record the Agencies note that groundwater downstream of New Lenox

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Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Road should be classified as GW -I because it is located greater than 500 feet from a public water system distribution pipeline However the Agencies agree that such groundwater need not be evaluated in the risk assessment because GE has demonstrated that groundwater in areas addressed in this risk assessment is not (and is not likely to be) contaminated by PCBs

The Agencies also note that in contrast to groundwater covered by this Human Health Risk Assessment Proposal for the Housatonic River groundwater underlying the GE facility and adjacent sites in Pittsfield is contaminated with PCBs and other hazardous materials and wiII be evaluated in separate risk assessments as part of site investigations for those areas

6 Fish are the only biota selected as a medium of concern based on the rationale that a risk assessment considering exposure to fish as the representative biota should represent a worstshycase analysis The Agencies agree that fish consumption wiII likely represent the highest risks from biota consumption However it is the Agencies view that consumption of biota other than fish (such as frogs turtles fiddlehead ferns ducks woodcock pheasant quail) should also be evaluated in the Risk Assessment The reasons for this are as foHows

There is a high level of interest and concern among members of the public about the risks associated with consumption of biota from the Housatonic River and floodplain The Risk Assessment should provide such information to the public

An evaluation of fish consumption does not rule out the possibility that there are significant risks from consuming other biota In order to make risk management decisions the Agencies must know if there are significant risks from consuming biota other than fish Risk management decisions regarding risks from consumption of biota other than fish might differ from risk management decisions about consumption of fish

GE should propose to evaluate consumption of biota other than fish All species which could potentially be consumed should be addressed in the risk assessment The Agencies recognize that there may not be sufficient consumption and tissue concentration data to allow quantitative assessment of exposure from consuming every species of concern It may therefore be necessary to evaluate exposures from some species qualitatively extrapolating from quantitative assessment of risks from other species GE should propose approaches for evaluating consumption of each species of concern in the revised workplan

7 The evaluation of fiddlehead fern consumption should consider the results of a study conducted for DEP by the Department of Food Science at the University of Massachusetts TIle study investigated the accumulation of PCBs by fiddlehead ferns growing in the Housatonic River floodplain where soil is contaminated with PCBs The Agencies wiII provide GE with a copy of the study protocol and results After GE has had an opportunity to review the material GE should propose either a qualitative or quantitative approach to assessing potential exposures and risks

42 Chemicals of Potential Concern

8 The Agencies and GE have agreed that this risk assessment will focus on derivation of riskshybased concentrations for the chemicals of concern in order to streamline the risk assessment GE should calculate risk-based concentrations for all substances detected at elevated concentrations in the river and floodplain adjacent to and downstream of the site TIms unlike most risk assessments conducted to meet DEP or EPA requirements risk estimates will not

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necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

necessarily be calcnlated for every substance GE wiII bear the burden of demonstrating however that any excluded substance is not elevated with respect to background For the purposes of the human health risk assessment for the Housatonic River the Agencies consider background to mean levels of contaminants which are present consistently and uniformly in the river upstreanl and downstream of GE (ie local conditions) Under this definition background can include contaminants resulting from other disposal sites permitted discharges and non-point sources For future reference this definition of background applies only to the River and floodplain Although this definition of background differs from that normally used by the Agencies its application to the River and floodplain wiII still be consistent with Agency policy and practice

9 Page 4-8 of the Risk Assessment Proposal states that GE wiII compare levels of chemicals at the Site to background levels using either summary descriptive statistics (as described in DEP Guidance 1995) or appropriate inferential statistical tests The Proposal further states that in appropriate cases where summary statistics do not show that the Site data are consistent with background GE will use inferential statistical techniques to make the comparison The Agencies wiII not consider the results of inferential statistical techniques as evidence that concentrations are consistent with background unless Site and background data sets have adequate sanlple size and the power of the statistical test is adequate

Section 50 Dose-Response

10 In Section 5 of the Proposal GE proposes to assess subchronic exposures to PCBs by evaluating exposures to a female of childbearing age during the nine months of pregnancy using a subchronic RfD that GE has developed (GEs subchronic RfD differs slightly from the subchronic RfD that is published on HEAS1) The Agencies believe that is important to include an evaluation of developmental effects to the fetus from exposures to PCBs in the risk assessment but that a sub chronic RfD may not be adequate to address potential developmental effects from PCBs

lu evaluating developmental effects to the fetus of a pregnant woman GE should use the chronic RfD for Aroclor 1254 unless GE can provide a credible and relevant justification based on new data (not previously evaluated by EPA) for an alternative RfD for developmental effects Although IRIS lists immune effects as the basis for the chronic RfD the EPA IRIS workgroup considered available data from developmental toxicity studies and concluded that the chronic RfD was also appropriate for assessing developmental effects (personal communication John Cicmanec) Risks from developmental effects of Aroclor 1254 are estimated from a supporting study (Levinskas 1984) The Agencies believe that use of the chronic RfD is preferable to the sub chronic RfD because there is no evidence that the subchronic RfD would be adequately protective of developmental effects If GE proposes an alternative RfD for developmental effects of PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

11 For all exposure scenarios involving outdoor exposures direct soil contact for example the risk assessment should include seasonal sub chronic exposure and risk estimates

12 EPA has recently completed a reassessment of the cancer potency of PCBs Rather than a single Cancer Slope Factor (CSF) for PCBs EPA has published 3 new CSFs all of which are

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lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

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X

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X

X

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SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

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SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

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ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

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Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

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ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

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bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

lower than the previous value of 77 per mgkgday (IRIS 1996) Different slope factors are intended to be applied to different exposure pathways EPA has published both central estimate and upper bound cancer slope values EPA states that central estimates describe a typical individuals risk while upper bound values provide assurance that this risk is not likely to be underestimated (IRIS 1996) The Agencies believe that the upper-bound CSFs are more appropriate for use in risk assessment than the central estimate CSFs The upper-bound CSFs are 2 per mgkgday 04 per mgkgday and 007 per mgkgday

These upper-bound CSFs should be used for the RMElFull Use risk estimates upon which the Agencies intend to rely as the primary basis for risk management decisions GE may however use the central CSFs to calculate central tendency risks

EPA provides guidance on choosing an appropriate CSF among the published values EPAs guidance for selecting an appropriate CSF is based on environmental processes (such as partitioning dechlorination and bioaccumulation) that can affect the mixture of PCBs present in a given medium Lower CSFs are suggested for pathways that are dominated by less toxic congeners EPA also provides the option for dermal exposure to soil of using a lower CSP instead of applying a dermal absorption factor EPA guidance also stipulates that evaluations of early-life exposure should use the highest CSF of 2 per mgkgday for all pathways and mixtures of PCBs

EPA guidance provides the following criteria for selecting an appropriate CSF

I Criteria for selecting the CSF of 2 per mgkgday

food chain exposures sediment or soil ingestion dust or aerosol inhalation dermal exposure (if an absorption factor has been applied separately) presence of dioxin-like tumor-promoting or persistent congeners and early-life exposure (all pathways and mhtures)

2 Criteria for selecting the CSF of 04 per mgkgday

ingestion of water-soluble congeners (not including PCBs attached to sediment particles) inhalation of evaporated congeners (not including PCBs attached to particulates) and dermal exposure (if no absorption factor has been applied separately)

3 Criteria for selecting the CSF of 007 per mgkgday

when congener or isomer analyses verify that congeners with more than 4 chlorines comprise less than 05 of the total PCBs

GE may use the new cancer potency information on IRIS in the human health risk assessment for the Housatonic River GE should follow EPA Guidance for selecting an appropriate CSF with the following specific clarifications

a) GE should use a CSF of 2 per mgkgday for direct contact with soil (ie soil ingestion dermal contact with soil and inhalation of particulates) and ingestion of biota The

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CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

CSF of 2 per mgkgday should be used for all dermal exposure to soil because the Agencies want the dennal absorption factor to be applied separately in the risk assessment calculations rather than as a value incorporated into the lower CSF of 04 per mgkgday This will make the risk assessment calculations more transparent and is consistent with how absorption factors are used for other contaminants and other media

b) As described in EPA guidance a CSF of 04 per mgkgday may be used for drinking water ingestion and vapor inhalation

c) As described in EPA guidance a CSF of 007 per mgkgday may be used when there are congener or isomer analyses for the PCB mixture of interest which verifY that congeners with more than four chlorines comprise less than one-half percent of total PCBs as well as the absence of dioxin-like tumor-promoting and persistent congeners

13 GE states on page 5-7 of the Proposal that the RID for Aroclor 1254 is not directly applicable to the predominant PCB mixture present at the site (ie Aroclor 1260) For the record theshyAgencies note that PCB mill-tures more similar to Aroclor 1254 than to Aroclor 1260 are a major contanlinant in fish from Connecticut portions of the Housatonic River In some cases levels of PCB mixtures resembling Aroclor 1254 exceed PCB mixtures resembting Aroclor 1260 in fish tissue (Interim Report Connecticut Department of Environmental Protection 1990)

Section 60 Exposure Assessment

14 Page 6-2 of the Risk Assessment Proposal states that the exposure assessment will focus on representative individuals witllin the receptor subpopulation whose activities represent full and unrestricted use of the site and who are most susceptible to contamination This is consistent with DEP policy In addition as previously stated in comment 4 in Section A GE must also estimate the Reasonable Maximum Exposure (RME) or High End Exposure (HEE) In the detailed comments which follow the Agencies have identified parameters which should be used in the risk assessment to evaluate RME or HEE exposures GE should note that guidance on RME and HEE assumptions is contained in EPAs Risk Assessment Guidance for Superfund Volume I Parts A and B listed in Attachment A EPA Region One Risk Update (EPA 1994) and EPAs 1992 Guidelines for Exposure Assessment also listed in Attachment A

15 GE has proposed to evaluate developmental effects on the fetus from maternal exposure to PCBs during pregnancy However pre-pregnancy exposures are not addressed in the Risk Assessment Proposal In the reproduction studies the EPA considered in establishing the chronic RID however body burden from pre-pregnancy exposures are incorporated The Risk Assessment Proposal should explain that pre-pregnancy exposures are accounted for in the assessment

16 Breastfeeding exposures are not addressed in the proposal although they are in fact included in the reproduction studies the EPA considered when the chronic RID was established TIle proposal should explain that breastfeeding exposures are taken into account in the risk assessment

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613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

613 Selection and Description of Exposure Scenarios

Residential 17 The Risk Assessment must include only one residential exposure scenario rather than the three

residential scenarios proposed by GE because the Agencies believe it is critical to have a consistent level of cleanup in all areas evaluated as residential

18 Consmnption of homegrown produce must be evaluated for all current and reasonably foreseeable future residential uses of the floodplain because residential cleanups should be protective for gardening

19 The ambient air inhalation pathway for the residential exposure scenario should include exposure to vapors and particulates Elimination of particulate inhalation exposure for residents may be reasonable if it can be demonstrated that inhaled particulates contribution to risk is insignificant (ie less than an order of magnitude below risk limits) relative to direct contact exposure routes (incidental ingestion and dennal contact) Elimination of particulates is contingent upon results of the lawn mowing evaluation (see comment number 22)

20 With regard to indoor dust exposures the Agencies do not agree with GEs contention that exposure to indoor dust is unlikely because residences are located far from the floodplain TIlere are residential properties on which Short Tenn Measures (ie Immediate Response Action to abate an imminent hazard) were perfonned where houses are located less than 50 feet from elevated levels of PCBs in soil

It is the Agencies view that exposure to PCBs in soil-derived indoor dust can comprise a significant fraction of overall PCB exposure from outdoor soil and that omission of indoor dust as a source of soil exposure could result in a serious underestimate of soil intake (DEP 1996 EPA 1994a) Therefore the Agencies believe it is necessary to quantifY indoor dust exposures in this risk assessment GE should evaluate indoor dust exposures to children aged 0lt6 years in the residential exposure scenario GE should propose an appropriate value to use for the proportion of indoor dust that is soil-derived

2l In the Risk Assessment Proposal GE has proposed a separate residential scenario to cover properties where portions of the 10-year floodplain extend into areas that are unsuitable for lawns now or in the future due to heavy vegetation andor steepness of the riverbank The Agencies will allow the use of lower assumptions for frequency and intensity of exposure in residential areas where physical limitations (for example steep riverbanks wetlands) are present Risks from exposures in portions of a residential property with physical limitations which reduce exposure must be evaluated in a separate recreational exposure scenario not as part of the residential scenario However the Agencies do not consider dense vegetation alone to be a physical limitation

22 Potential exposures to residents from inhalation of airborne particulates from lawn mowing has not been included in the residential scenario Given the high level of interest among the public regarding potential exposures to PCBs from lawn mowing and the potential for lawn mowing over thin or bare lawn areas to generate airborne particulates GE must propose a methodology for evaluating such exposures and evaluate them in the risk assessment

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Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

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The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

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12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

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Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

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SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

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SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

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SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

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ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

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ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Recreational 23 The Agencies recommend developing a combined recreational assessment for activities that

involve direct contact with floodplain soil For example a single set of exposure parameters could be used to evaluate exposure to floodplain soilsediment during picnicking walking hiking and fishing This exposure scenario would represent combined recreational exposures for any receptor engaging in one or more of these activities An exposure frequency of two days per week should be used for this assessment By eliminating the need to detennine which specific recreational activity or combination of activities is foreseeable at each location this approach would simplifY the risk assessment and facilitate risk management decisions in recreational areas

24 Based on the results of a screening analysis to detennine the relative contribution of the ambient air inhalation pathway (ie inhalation of volatile PCBs) GE is proposing to exclude inhalation of ambient air as a pathway of concern for recreational scenarios TIle screening analysis perfonned by GE indicates that the contribution to risk from inhalation of ambient air is negligible when compared to the contributions from soil ingestion and dennal contact

It is not common Agency practice to eliminate an exposure pathway from a site-specific risk assessment based on the risk of that pathway relative to the risks from other exposure pathways because the Agencies are interested in the total risks posed to a receptor by the site In addition there is a high level of concern among the public regarding the risks from ambient air For these reasons the Agencies believe that the ambient air inhalation pathway should be included in the risk assessment

For recreational scenarios that involve specific exposure to soil-derived particulates (as opposed to ambient air generally) the Agencies would agree that elimination of particulate inhalation exposure route may be reasonable if it can be demonstrated that inhaled particnlates contribution to risk is insignificant relative to direct contact exposure routes (incidental ingestion and dennal contact) However PCB vapors in the ambient air comprise a separate exposure pathway Vapor inhalation contributes to cumulative PCB ellosure for all scenarios and vapor exposures will have to be taken into account for all risk management decisions Regardless of whether vapor risks are low relative to risks from other exposure pathways vapor exposure should be included in the risk assessment for completeness

Dirt Biking 25 The Risk Assessment Proposal shonld not assume that dirt biking is limited only to areas

which currently have dirt bike trails Dirt biking must be considered a reasonably foreseeable use in any area unless there is a clear limitation on dirt biking In coordination with Agency project managers GE should systematically identifY and map floodplain areas where dirt biking is foreseeahle

Swimming 26 The swimming scenario described on page 6-10 should include incidental ingestion of water

Agricultural 27 TIle Risk Assessment Proposal should not assume that farming activities are limited to two

current fanns located upstream of Woods Pond Farming activities must be considered a reasonably foreseeahle use in any area unless there is a clear limitation on fanning uses The likelihood of converting land in different areas to agricultural use in the future should be evaluated separately for different types of agriculture (for example dairy fanning which

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should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

should include exposure to home produced meat produce fanning chicken fanning egg production) In coordination with Agency project managers GE should systematically identifY and map floodplain areas where each type of agricultural use(s) is reasonably foreseeable and should provide justification for excluding the remainiug areas The Agencies note that a farm need not be limited to a large plot of land Agricultural uses or activities such as middotsmall market produce gardening can occur on a relatively small property TIle Agencies expect GE to consider this when identifYing areas where agricultural uses are foreseeable

Construction Worker 28 The Risk Assessment Proposal does not include a Construction Worker Scenario based on the

rationale that construction will not occur in the floodplain The Agencies disagree Bridge and road maintenance are examples of construction activities that will occur in the floodplain and could result in exposures to PCBs In addition there is at least one waste water treatutent plant located in the floodplain Construction activities have and will continue to occur at this plant TIle risk assessment should evaluate construction worker exposures in all locations where construction activities are reasonable In coordination with Agency project managers GE should systematically identifY and map floodplain areas where construction exposures are likely

621 Identification of Exposnre Points

29 The lists of exposure points must include Oxbows within the lO-year floodplain that are not included in any of the GE facility sites and that are not being addressed as separate sites

30 On page 6-14 five floodplain reaches have been identified as exposure points for residential scenarios This approach to defining an exposure point is not consistent with current DEP guidance and practice An exposure point is a location or area where a receptor comes into contact with contamination TIle exposure point should be an area within which a receptor has an equal likelihood of exposure For the residential scenario an exposure point must not be larger than a single property since a residential receptor may have an equal likelihood of exposure in hislher own backyard but not in the backyards of neighbors

3l It is unclear whether the list of exposure points on page 6-15 for the walkerlhiker scenarios is intended to be a comprehensive list or simply to provide examples As stated previously walkinglhiking activities must be evaluated as a reasonably foreseeable use in any area where walkinglhiking is possible Specific examples of exposure points which should be evaluated as current use for the walkinglhiking scenario are the sewer easement in the Dawes Avenue to Holmes Road reach and the railroad tracks and dirt road in the Woods Pond floodplain

32 TIle following potential additional canoe access points above Woods Pond were not included in the list on page 6- I 6 of the Proposal

Joseph Drive neighborhood and access road leading to the Pittsfield Wastewater Treatutent Plant

The risk assessment must evaluate canoeing exposures from the additional access areas identified above and any other known canoe access point

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622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

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middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

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The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

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12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

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Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

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SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

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SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

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SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

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ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

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Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

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ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

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bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

622 Development of Exposure Point Concentrations

33 For purposes of estimating Exposure Point Concentrations (EPCs) in soil and sediment GE has proposed only to use data from 0-6 inches (ie omitting data from all depths greater than 6 inches) for all scenarios except residential and utility worker For residential exposures GE has proposed only to use data from 0-12 inches (ie omitting data from all depths greater than 12 inches) For the utility worker GE has proposed to use data from all depths

The Agencies disagree with GEs proposal to limit data used to calculate EPCs GE should estimate EPCs in soil based on all data that have been collected within the vertical extent of contamination from 0 to 15 feet

Residential and Recreational For the residential and recreational scenarios separate soil EPCs should be estimated for two depth intervals the 0 to I foot depth interval and the interval from I foot to the etent of contamination up to 15 feet

TIle 0 to I foot interval represents the most accessible surficial soil where exposure is likely to occur with the greatest frequency and intensity For this reason the surficial soil EPC should be limited to the average contaminant concentration in the top 12 inches of soil in the exposure area

Commercial Worker For the commercial worker scenario EPCs for surficial soil should be estimated based on data from the 0 to I foot interval A separate EPC for deeper soils should be calculated using data from the interval from I foot to the depth of contamination up to 6 feet For contaminated soil at depths greater than six feet the risk assessment can assume that exposure to such soils will not occur (ie excavation will not occur)as long as an institutional control (AUL) is placed on the property by the owner The AUL serves as a notice that prior to excavation occurring in the future potential exposures from such excavation must be evaluated TIle Agencies note that such a limitation should not preclude activities which may be needed in order for redevelopment of commercial property to occur

Utility Worker For the utility worker scenario GE has proposed to use data from all depths of contamination The Agencies agree with this proposal and add that the Agencies consider it acceptable for GE to calculate the EPC as the average concentration across the entire depth of contaminated soil

Construction Worker For the construction scenario that the Agencies have asked GE to evaluate in the risk assessment an EPC should be calculated as the average soil or sediment concentration within the 0 to I foot depth interval and within the interval from I foot to the vertical extent of the contamination up to 15 feet

The Agencies are recommending the use of a zero to one foot interval for surface soil exposure point concentration estimates even though it is Agency policy to use a smaller interval typically zero to six inches This recommendation also deviates from usual practice of calculating a separate exposure point concentration for each of three different depth intervals

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The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

The Agencies recommendation represents an effort to simplifY exposure point concentration and risk calculations For exposure points where sutface soil data has already been collected from the 0 to 6-inch interval those concentrations may be used to represent sutface soil exposures

The Risk Assessment must assume that less accessible soils are brought up to the sutface (through activities such as excavation) where exposure occurs with the same frequency duration and intensity as surficial soils unless there is a clear limitation on excavation

As is the case for any soils Massachusetts Upper Concentration Limits (UCLs) must be met in order to achieve a pennanent solution under the Massachusetts Contingency Plan (MCP)

34 GE has proposed to use the nearest neighbor (Theissen polygon procedure) for calculating spatial averaging but if the procedure proves too imprecise GE proposes to use one of four other more complex methods Spatial averaging is not appropriate if the data at a given exposure point are not sufficient to warrant this approach In determining EPCs for soil and sediment GE must calculate the 95 percent upper confidence level (UCL) of the mean EPAshyguidance outlines the procedure for calculating the 95 percent UCL (EPA 1994) GE may use other values if it provides a justification for use of a different approach for a given exposure point considering the quantity of data available for such exposure point and the Agencies agree

35 For puzposes of estimating the ambient air EPC for the residential exposure scenario GE proposes to adjust floodplain air concentration (measured in Fred Gamer Park) to account for dispersion as PCBs in floodplain ambient air are transported from the floodplain to nonshyfloodplain portions of residential commercial or agricultural properties The Agencies disagree with this method of estimating the EPC because it is based on a generic assumption about how much of a property is within the floodplain This could underestimate the EPC at some locations To avoid underestimating EPCs GE should use the average measured air concentration in Fred Gamer Park as the ambient air EPC for all areas of a property If GE does not want to use data from Fred Gamer Park GE may take air samples in residential floodplain properties

36 GE has not described how it will estimate EPCs for fish consumption other than to say that an average will be calculated for fish from each of six reaches plus hot spots (if any) In addition to calculating the EPC for fish from the average tissue concentration across all species from each reach GE should include the species-specific tissue concentrations in the risk assessment report GE should include fish species in the EPC calculation that are not considered traditional game fish species

For the subsistence fishing scenario (described in comment 48) GE must also calculate an EPC which includes fish species that are not considered traditional game fish species and which accumulate PCB to a greater degree (such as white sucker)

64 Exposure Parameters

37 GE has proposed to adjust the exposure frequency downward for hotspots to reflect the proportion of the total site area represented by the hot spot This is not acceptable to the Agencies The Risk Assessment must evaluate exposure to hotspots as a separate exposure point not relative to the total site area The rationale for this is 1) exposure might be higher

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at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

at a hotspot in the future (for example a garden or swing set could be placed in the hotspot area and 2) reducing the frequency of exposure at a hotspot has the same effect as averaging over the larger area and thus defeats the purpose of evaluating hotspots separately

38 GE is proposing to use a time-weighted exposure frequency for direct contact with soil in the residential exposure scenario to account for lower exposure frequency during the cooler months of April May September and October when school is in session GEs proposed timeshyweighted frequency assumes that adults and older children (ages 6-10 years) spend time in their yards 5 days per week for three months and two days per week for four months (100 days per year) GE assumes that very young children (1-5 years) spend 5 days per week for three months and three days per week for four months (117 days per year) The Agencies believe that children may spend fewer hours per day in their backyards during months when school is in session but the Agencies do not agree that the number of days per week a child visits hislher backyard will be less when school is in session

The Agencies believe that GEs proposed time-weighted exposure frequency assumptions do not adequately characterize individuals whose activities represent a full and unrestricted use uf the site The risk assessment should use an exposure frequency of 5 days per week for 7 months a year (April through October) because it better represents full and unrestricted residential use of the site TIlis is DEPs default assumption for exposure to contaminated soil at a residential property (DEP 1995) It is also consistent with the Region I default residential exposure frequency of 150 days per year

The Agencies agree that it is reasonable to assume that there is less dermal contact during the months of April May September and October because the weather is cooler than during June July and August and a receptor will likely be wearing more clothes

39 GE proposes to adjust downward by 50 the daily soil ingestion rate for the 1-5 year old based on an assumption that one-half the daily ingestion rate is attributable to ingestion of outdoor floodplain soil and the remainder is attributable to indoor dust (GE also makes the assumption that indoor dust is uncontaminated because residences are located far from contaminated floodplain soil) GE proposes to make this adjustment to soil ingestion in the residential and walkerlhiker scenarios

The Agencies do not agree with GEs proposal for the following reasons First as has been communicated to GE on several previous occasions the Agencies do not allow reduction of soil ingestion rates to account for time spent in uncontaminated areas Soil ingestion rates should always be used as daily rates because the studies on which the soil ingestion rates are based do not indicate whether soil ingestion is a sporadic event or whether it occurs evenly throughout the exposure period

Secondly as stated previously in comment 20 the Agencies disagree with GEs assumption that indoor dust is uncontaminated There are residential properties on which houses are located less than 50 feet from elevated levels of PCBs in floodplain soil As also stated in comment 20 the Agencies have asked GE to evaluate indoor dust exposures in this risk assessment

40 GE has proposed to use soil ingestion rates of 50 mgday for adults and 100 mgday for children TIle Agencies agree that these values are appropriate at this site as estimates of average soil intake Under RCRA Proposed Guidance (EPA 1996) EPA can agree to stateshy

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based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

based default values when they are consistent with the site-specific conditions at the facility in question For the sake of consistency and given the distribution of PCBs in the floodplain the Agencies agree with GEs proposal to use soil ingestion rates of 50 and 100 mgday The Agencies have agreed upon these soil ingestion rates for the floodplain only and it should not be viewed as a precedent for other sites TIle Agencies will not approve the use of soil intake reduction factors (such as an adjustment for percent of soil ingestion attributable to indoor dust)

41 DEP Guidance (July 1995) is cited as the source for assumptions about the fraction of total vegetable consumption that is attributable to homegrown produce However DEP Guidance provides homegrown fractions for individual vegetables rather than categories of vegetables GE should clarify how the default values in DEP Guidance were modified to get the values presented in the Risk Assessment Proposal

42 The vegetable consumption rates in Table 6-4 of GEs Proposal are based on mean values reported by Pennington (1983) GE should clarify whether the values in Table 6-4 are wet weight or dry weight

43 Clarification is needed regarding the units for the plant uptake factors in Table 6-4 The uptake factors in Table 6-4 are expressed as percentages However in the equation on page 6shy23 the plant uptake factor is listed as unitless If the plant uptake factor is nnitless the units in the equation as currently written do not cancel properly DEP (and many of the literature sources cited by GE) express uptake factors in units of (mghmiwkg plMJ per (mghmiwkgdY ~oil) or (flghmiwg plMJ per (flghmi~gdY oil) rather than as percent GE should express the plant uptake factors in units consistent with the equations presented in the Proposal Doing so will allow the Agencies to compare its default values and the values GE has proposed to use

44 GE has assumed an exposure frequency of one day per week for the walkinglhiking and picnicking scenarios TIle Agencies believe that the risk assessment should use two days per week for these scenarios because it is a frequency that is more representative of full and unrestricted use of floodplain areas for such recreational activities

45 GE has correctly reported tlmt the Agencies stated in previous discussions that they would accept the use of all waters (ie rivers and streams and lakes and ponds) freshwater fish consumption data from the Ebert study (Ebert et aI 1993) study However the Agencies also have stated previously that the risk assessment should evaluate exposure to recreational anglers who use the Housatonic River to the fullest extent This is consistent with the MCP (310 CMR 400923) which states that the risk characterization should describe the full extent of site activities consistent with an identified site use The Agencies believe that the evaluation of exposure to recreational anglers from ingesting contaminated fish should focus on the subgroup of anglers who eat a relatively large amount of fish from the waterbody of concern Thus the fish consumption rate should represent an average or typical intake rate for this high-use group

The Agencies previously stated that the ideal way to obtain a high-use average is to calculate the average of all the consumption rates that fall at the high end of the angler population intake range (for example above the 80th percentile) The Agencies previously recommended that GE calculate such a value from the Ebert study and if GE chose not to calculate such a value an intake value of 26 grams per day should be used in the risk assessment The value of 26

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glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

glday represents the 95th percentile consumption rate from the Ebert study for fish from all waters and assumes that the angler shares hislher entire catch with family members

TIle Agencies have re-evaluated the available information and agree that GE may use the 95ile consumption rate for rivers and streams rather than all waters After further consideration the Agencies have agreed that assuming that each angler shares hislher catch with family members thus reducing the individual consumption rate may not be representative of the consumption rate for the high use group Therefore GE should use the 95th percentile consumption rate for rivers and streams only and should not use a sharing factor to reduce the individual consumption rate A value of 27 gday represents the 95ile consumption rate for rivers and streams with anglers as the only consumers (Ebert et al 1993)

A value of 27 glday represents one 8 ounce fish meal slightly over 3 times per month The Agencies consider 27 glday to be protective of the high use subgroup of recreational anglers Considering other recreational freshwater angler studies published in the scientific literature the Agencies do not view 27 gday to be an overly protective value The value of 27 glday is consistent with rates reported in other studies of freshwater fish consumption among recreational anglers (West et al 1989 Connelly et al 1990 Fiore et al 1989) It is the Agencies view that 27 gday does not represent an overly conservative estimate of average fish consumption among high use anglers

In the Uncertainty Section of the risk assessment GE should discuss variability in fish consumption rates and should present a range of risks using alternative assumptions about fish consumption Such information could be quite helpful for risk communication pUlposes

In the uncertainty section GE should also discuss the impacts that a single fish consumption rate for all ages might have on the risk estimate (ie a single fish consumption rate could overestimate actual consumption by a child and could underestimate adult consumption)

46 The results of the Housatonic River creel survey can be used as a basis for current exposure frequency and duration assumptions for fishing in the Massachusetts portion of the Housatonic River given the fish consumption ban currently in place However it is not appropriate to use as a basis for assumptions about fishing frequency and duration in Massachusetts in the future because at a minimum of the fish consumption ban that is in place If recreational anglers could eat tlle fish tlley caught in the Housatonic River it is likely that they would spend more time fishing and would fish more frequently than tlley do with the consumption ban in place

As stated previously the Agencies recommend using an exposure frequency of two days per week for a common recreational scenario that is protective for all recreational activities involving direct soilsediment contact (walking hiking picnicking fishing) This recommendation is offered in tlle interest of simplifYing tlle risk assessment and tlle risk management decisions that are to be based on the risk assessment

However if GE does not opt to use the simplified recreational scenario it should propose a fishing frequency tllat is representative of full and unrestricted use of the River based on available data on fishing frequency in comparable waters that are not subject to a fish consumption ban If such data are not available a fishing frequency of 3 days per week (May through September total of 66 days per year) should be used to represent full and unrestricted use of the River (personal communication Tom Keefe Massachusetts Division of Fisheries and Wildlife November 15 1996)

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47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

47 GE has proposed to evaluate two scenarios for anglers in Connecticut (1) one which assumes that no fish are consumed (ie anglers comply with the fish consumption advisory) and (2) one which assumes that fish are consumed (ie anglers do not comply with the fish consumption advisory) The Agencies disagree with the first fishing scenario because the scenario does not accurately represent the fish consumption advisory in the Connecticut portion of the River In Connecticut the consumption advisory applies only to selected fish species in specific areas Thus GEs evaluation of risks to anglers who comply with the fish consumption advisory should assume that anglers consume fish that are not included in the advisory (for example yellow perch from the Bulls Bridge area and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory) GEs evaluation of risks from recreational fishing should include separate calculations for each species and river sectionimpoundment for which suitable fish tissue data are available

48 GE should evaluate risks to subsistence fishermen as part of the risk assessment GE should evaluate subsistence fishing exposures using fish consumption rates of 60 g1day for central tendency consumption and 140 gday for high end (RME) consumption These values have been developed by EPA based on review of the literature on fish consumption by Native Americans and subsistence anglers (EPA 1995) Comment 36 describes how the Agencies want EPCs to be calculated for the subsistence fishing scenario

TIle Agencies acknowledge that currently available information does not indicate that subsistence fishing popUlations are using the Housatonic River However at this point in time the available information is not sufficient to justify ruling out subsistence fishing now or in the future If further investigation shows that subsistence fishing is not practiced and would not be reasonably foreseeable even in the absence of fish advisories the subsistence fishing risk estimates will not be considered in risk management decisions Further there is a high level of interest and concern among members of the public about the risks associated with subsistence fishing TIle Risk Assessment should provide such information to the public GE could present the results of a subsistence fishing evaluation in the Risk Perspective Section of the Risk Assessment

49 As stated on page 6-38 GE has proposed to consider the reduction of PCB concentrations in fish resulting from various cooking methods TIle reduction in PCBs in fish caused by cooking is not a true loss because although some PCBs may volatilize during cooking most of the PCBs will remain in the fat drippings For these reasons the Agencies believe a cooking reduction factor is not justified Thus the risk assessment should not consider a reduction of PCB concentrations in fish resulting from cooking

In tile Uncertainty Section of the risk assessment GE may present an estimate of the magnitude of the change in risks that could result if a person consumed only fish flesh and not fat drippings Such information could be quite helpful for risk communication purposes

50 For inhaled particulates (PMlO) GE has proposed to use a lung deposition fraction of 125 and an ingestion fraction of 625 for dirt bikers utility workers and agriCUltural workers The fractions proposed by GE are somewhat different from values used by the Agencies The Agencies assume that 50 of the inhaled particulate mass (PM10) is deposited in the lung (US EPA 1986) and as a default assumption it is assumed that the remaining 50 of the PMlO is transferred to the gastrointestinal tract (DEP 1996) Since GE will be using the sanle toxicity values and absorption factors for inhaled and ingested doses the Agencies do not expect that the risk result using GEs deposition and ingestion fractions will be significantly

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different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

different from the result using the Agency default values Therefore the Agencies consider GEs proposed deposition and ingestion fractions to be acceptable for use in the risk assessment

51 TIle Agencies agree with GEs assumption that an individual wiII only swim in the Honsatonic River on an occasional basis but disagree with the rationale presented in the Proposal (ie that GE and their contractors have never observed people swimming in the river in Woods Pond or upstream of Woods Pond) The Agencies rationale for why svimming is likely to occur only on an occasional basis is based on the fact that designated sMmming beaches are not currently present on the River or in Woods Pond and are not likely to be created in the future because of the Rivers current and shallow depth These qualities make the River an undesirable location to create a swimming beach However these qualities do not necessarily make the River undesirable for wading and playing along the riverbanks especially in areas where there are residences close to the river

GE has proposed to evaluate exposures to both an adult swimmer and a child swimmer GE has proposed to assume that the adult swimmers entire body surface comes into contact with the water and only minimal contact to sediment occurs TIle Agencies agree with GEs proposed assumptions for the adult swimmer GE should present risks to the adult swimmer separately from the child swimmer

Regarding swimming exposures to children GE has proposed to assume that the hands feet and legs of a child are exposed to sediment The Agencies believe that children will also contact sediment with their arms while wadingplaying and swimming TIlliS GE should include sediment exposure to arms in the child swimming scenario

52 GE states that exposures in the commercial scenario are limited to commercial establishments that are located some distance from the floodplain The commercial scenario should also cover current and reasonably foreseeable future use of floodplain soils for commercial purposes In coordination with Agency project managers GE should systematically identify and map the areas where commercial enterprises are reasonably foreseeable and should justify the elimination of floodplain areas from the assessment of commercial exposures To the extent that the possibility of commercial exposures entirely within the floodplain cannot be ruled out the risk assessment should evaluate those exposures In such a scenario there are a variety of activities that could result in a commercial worker being exposed to floodplain soil TIlliS GE should evaluate the outdoor worker who is likely to receive relatively intense exposure (for example landscaping exposures)

53 GEs assumption that no more than 25 of the cultivated fields (for the one active farm for which floodplain soil data is available) are located in the floodplain may be appropriate for current agricultural use but not necessarily for future use The Risk Assessment must evaluate agricultural exposures for a future agricultural scenario in which as much as 100 of the cultivated fields are assumed to be located in the floodplain if such a future scenario is reasonably foreseeable As part of the mapping exercise discussed in comment 27 above GE should identify floodplain areas where agricultural use is reasonably foreseeable and should determine the maximum fraction of arable land in those areas that is contained within the floodplain and use such assumptions to evaluate potential exposures in the agricultural scenario

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54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

- 23 shy

hhcomJin 7124)7

ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

54 The Agencies do not agree with GEs assertion that because fanners maintain acres of cropland using fann equipment rather than by working their cropland by hand the exposed skin surface area for a fanner is limited to areas that may be exposed to dust generated by fann equipment Airborne particles settling on the skin surface are one potentially significant direct contact pathway The Agencies believe that a fanners direct contact with soil is likely to be great because of the frequency and intensity of the fannworkers activities The Agencies believe that the skin surface areas GE proposes to use for this scenario (hands forearms and 25 of the head and neck) are reasonable for the central estimate of exposure For the RME GE should assume that 25 of the total skin surface area comes into contact with soil

55 GE should use an exposure time of 12 hours per day for inhalation of particulates by funners to be consistent with the assumption that adults work on cultivated land for 12 hours per day

56 GE has not provided the incidental soil ingestion rate it intends to use for the agricultural scenario DEP and EPA have a default enhanced soil ingestion rate for the adult farmer of 480 mgday GE should use this value unless it can provide a credible and relevant justification for an alternative site-specific enhanced ingestion rate If GE decides to propose a site-specific enhanced soil ingestion rate GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

57 Based on the rationale provided in comment 53 above GE must assume that 100 of the total corn diet fed to dairy cattle is grown on floodplain soils to the eient that the mapping exercise conducted in coordination with Agency project managers identifies areas where it is reasonably foreseeable that I 00 of the cropland could be located in the floodplain

58 GE assumes that the only potentially contaminated forage feed is corn GE should evaluate potential exposure from other crops such as hay and grass that may constitute substantial fractions of the diets of the dairy and beef cattle Potential exposures from foraging (incidental ingestion of contaminated soil) should be considered

59 It appears that the selection of 01 for dust contamination on corn silage does not consider soil intake that would occur while cattle are grazing on forage feeds other than corn GE should evaluate soil intake from grazing on forage feeds other than com

60 Clarification is needed regarding the units for the tenns in the equation on page 6-24 for calculating the concentration of PCBs in cow milk If the tenn Cs refers to the concentration of PCBs in soil then the units in the equation as currently written do not cancel

61 GE has proposed to use a bioconcentration factor (BCF) of 46 (a unitless value) to relate the concentration of PCBs in a cows diet with the concentration of PCBs in a cows milk TIle Agencies note that a more conventional way to express a BCF for cows milk is in the units mgpCBIkgoow milk per mgpCB inday GE should express the BCF for cows milk in the more conventional units Doing so will allow the Agencies to compare its default value with the value GE has proposed to use

GE should obtain data (if tl1ey exist) on PCB concentrations in cows milk from the fonner dairy fann located at parcel 29-1 GE should use such data in evaluating uncertainty in the model used to estimate PCB concentrations in cows milk

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hhcoJlllin 72497

6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

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hhcomiin 7124197

REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

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hhcoI11fin 7124lt)7

EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

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hhcomJin 7124)7

ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

6415 Bioavailability

62 GE has proposed to use 146 and 143 for the dermal absorption of PCBs in soil and sediment respectively The Agencies disagree with these values Recent information in the literature leads the Agencies to believe that dermal absorption of PCBs in soil and sediment is much higher than the values GE has proposed to use in the risk assessment (Wester et aI 1993) Based on the data in the Wester study the Agencies believe that 14 is a protective value for dermal absorption of PCBs in soil and sediment This value may not be modified based on the organic carbon content unless GE can provide basic research in dermal toxicology which demonstrates a reduced absorption with higher organic carbon GE must use the value of 14 unless it provides a credible and relevant justification for an alternative dermal absorption value If GE decides to propose an alternative dermal absorption value for PCBs GE must submit such a proposal to the Agencies for review within 30 days of receipt of the Agencies final comments on the Human Health Risk Assessment Proposal

732 Suitably Analogous Standards

63 GE correctly states that the Ambient Water Quality Criteria relevant to the Human Health Risk Assessment are those established for protection of human health The Agencies note that the Ambient Water Quality criteria for protection of aquatic life are applicable in the ecological risk assessment and that a sitecspecific ecological risk assessment does not eliminate the need to meet such criteria

Preliminary Risk Management Goals

64 Connecticut DEP hazardous waste cleanup regulations state that individual chemicals should contribute no more than I x 10-6 excess lifetime cancer risk (ELCR) to the overall risk at a site GE should note that in the Connecticut portion of the Housatonic River risk management decisions must be consistent with Connecticut standards and policies

- 21 shy

hhcomiin 7124197

REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

- 22 shy

hhcoI11fin 7124lt)7

EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

- 23 shy

hhcomJin 7124)7

ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

REFERENCES

CT DEP Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River

Connelly NA TL Brown and BA Knuth New York Statewide Anglers Survey New York State Department of Environnlental Conservation 1990

DEP 1992 Documentation For The Risk Assessment Shortform Residential Scenario Massachusetts Department of Environmental Protection Office of Research and Standards and the Bureau of Waste Site Cleanup Policy WSCORS-142-92 October 1992

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCORS-95-141 July 1995

DEP 1996 draft Soil Contaminant Levels and Risk To Human Health Massachusetts Department of Environmental Protection Office of Research and Standards April 1996

Ebert ES NW Harrington KJ Boyle JW Knight and RE Keenan Estimating Consumption of Freshwater Fish among Maine Anglers North American Journal of Fisheries Management 13737-745 1993

EPA 1986 Review of the National Ambient Air Quality Standards for Particulate Matter US Environmental Protection Agency Office of Air Quality Planning and Standards EPA 45005 86shy012 1986

EPA 1989 Risk Assessment Guidance for Supeljimd Volume I Human Health Evaluation Manual (Part A) interim final EPA 54011-89002 December 1989

EPA 1992 Dermal Exposure Principle and Applications Exposure Assessment Group Office of Health and Environmental Assessment US Environmental Protection Agency (EPAl6008shy910IlB) Interim Report January 1992

EPA 1994 us EPA Region One Risk Update Number 2 August 1994

EPA 1994a Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPAl540r-93081 Office of Emergency and Remedial Response Washington DC 1994

EPA 1995 Water Quality Guidance for the Great Lakes System SupplementGlY Information Document (SID) EPA Office of Water EPA-820-B-95-001 March 1995 page 575

EPA 1995a EPA New England Risk Update Number 3 August 1995

- 22 shy

hhcoI11fin 7124lt)7

EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

- 23 shy

hhcomJin 7124)7

ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

EPA 1996 PCBs Cancer Dose-Response Assessment and Application to Environmental Mixtures National Center for Environmental Assessment Office of Research and Development US Environmental Protection Agency NCEA-W-059 External Review Draft January 1996

EPA 1996 Proposed Rules for Corrective Action for Releases fiom Solid Waste Management Units at Hazardous Waste Management Facilities Federal Register p 19449 Vol 61 No 85 Wed May I 1996

Fiore BJ HA Anderson LP Hanrahan LJ Olson and WC Sonzogni Sport Fish Consumption and Body Burden Levels of Chlorinated Hydrocarbons a Study of Wisconsin Anglers Archives of Environmental Health 44 82-88 1989

IRJS 1996 Integrated Risk Infonnation System

Levinskas GJ DP Martin HR Seibold and JL Cicmanec 1984 Arocor 1254 Reproduction study with Rhesus monkeys ~acaca mulatta) Unpublished study by Monsanto

Wester RC HT Maibach and L Sedik 1993 Percutaneous absorption ofPCBs fiom soil in vivo in rhesus monkey in vitro in human skin and binding to powdered human strateum corneum J of Toxicology and Env Health vol 39 no 3 pp 375-382

West PJ M Fly R Marans and F Larkin Michigan Sport Anglers Fish Consumption Survey Report to Michigan Toxic Substances Control Commission Natural Resource Sociology Research Laboratory Ann Arbor MI 1989

- 23 shy

hhcomJin 7124)7

ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

ATIACHMENT A

A EPA Risk Assessment Guidances

The human health risk assessment of the Housatonic must take into account the guidance procedures assumptions methods and fonuats contained in

US EPA-Region I Waste Management Division Risk Updates

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment and Part 2 Ecological Risk Assessment (EPA 9015-89001 June 1989)

Human Health Evaluation Manual Supplemental Guidance Standard Default Exposure Factors (EPA OSWER Directive 92856-03 March 25 1991)

Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (RAGS HHEM)

(Part A) interim final (EPA 5401-89002 December 1989)

- Development of Risk-Based Preliminary Remediation Goals (Part B) (EPA Publication 92857-0IB December 1991 PB92963333)

Risk Evaluation of Remedial Alternatives (Part C) (EPA Publication 92857-01C December 1991 PB92-963334)

Calculating the Concentration Tenu Supplemental Guidance to RAGS (EPA Publication 92857-081 May 1992)

Guidance for Data Useability in Risk Assessment Part A (EPA Publication 92857-09A April 1992 PB92-963356)

Guidance for Data Useability in Risk Assessment Part B (EPA Publication 92857-09B May 1992 PB92-963362)

Denual Exposure Principle and Applications (EPN6008-91101lB January 1992)

AirSuperfund National Technical Guidance Study Series Volumes I II III and IV (EPA 4501-89shy001002003004 July 1989)

Guidelines for Exposure Assessment (57FR22888 - 57FR22938 May 29 1992)

Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children EPA OERR Publication Number 92857-15-1 PB93-96351O available through NTIS (703487-4650)

Integrated Exposure Uptake Biokinetic Model (JEUBK) Version 099d EPA OERR Publication Number 92857-15-2 PB93-963511 available through NTIS (703487-4650)

A - I

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Land Use in the CERCLA Remedy Selection Process (EPA OSWER Publication 93557-04 May 25 1995 PB95-963234)

Exposure Factors Handbook (EPN6008-891043 March 1989)

Additional EPA Guidances that may be used to prepare the risk assessment are as follows

Guidelines for a Carcinogen Risk Assessment (51 FR 33992 September 24 1986)

b Mutagenicity Risk Assessment (51 FR 34006 September 24 1986)

c The Health Risk Assessment of Chemical Mixtures (51 FR 34014 September 24 1986)

d The Health Assessment of Suspect Developmental Toxicants (51 FR 34028 September 24 1986) and

e Exposure Assessment (57 FR 22887 1992)

B DEP Guidance

DEP 1995 Guidance For Disposal Site Risk Characterization In Support of the Massachusetts Contingency Plan Massachusetts Department of Environmental Protection Bureau of Waste Site Cleanup and Office of Research and Standards Interim Final Policy BWSCIORS-95-141 July 1995

A - 2

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

AlTACHMENT B

TIe following is a summaty of the general EPA fonnat and content requirements for draft and final Human Health Risk Assessment Reports

The Health Risk Assessment must address the following five categories at a minimum

1 hazard identification 2 dose-response assessment 3 exposure assessment 4 risk characterization and 5 limitationsnncertainties

The Human Health Risk Assessment shall be based upon information gathered during the RFI investigation at the site as well as on data available through peer-reviewed literature Collection of additional field data to support the Human Health Risk Assessment may be necessary The decision regarding the need for supplemental data collection will be made after review of the Phase I RFI data by EPA TIle facility shall collect additional field data only at the direction of the EPA Work Assignment Manager Primary importance will be placed upon data collected in the field at the site with data collected from the literature used to support or explain field results

CONTENTS OF THE DRAFT AND FINAL HUMAN HEALTH RISK ASSESSMENT REPORTS

The final product shall be the Human Health Risk Assessment Report comprised of the completed human health risk assessment Prior to submission of the final report portions of the Assessment in the form of a draft (as described below) shall be submitted Once the draft is accepted the Risk Assessment Report shall be submitted This shall include text and tables from the draft as well as the additional information required to finish the report

Draft Human Health Risk Assessment Report

1 Hazard Identification I

The objective of this component is to present an orderly compilation of the available sampling data on the hazardous substances present at the site to identify data sets suitable for use in a quantitative risk evaluation and to identify chemicals of concern upon which the quantitative assessment of risk will be based

TIlis section shall contain information identifying the extent and magnitude of contamination in each medium Summaries of the sampling data shall be generated for each constituent detected in each medium indicating the mean the 95 UCL of the mean (see Calculating the Concentration Term Supplemental Guidance to RAGS) and maximum concentrations (including location of the latter) sample quantitation limits (or detection limits if not available) frequency of detection identification of any appropriate regulatoty criteria (MCLIMCLGs) and the number of times the regulatoty criteria is exceeded ill addition pictorialgraphic displays of the data are strongly encouraged TIle format of these displays

B-1

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

middot will be dependent upon site specific factors and will be detennined with the approval of EPAs risk assessor and project manager See Sample Table I

Only when the number of contaminants detected is so large that quantitation of health risks for each contaminant would be infeasible should any screening be used to eliminate potential contaminants of concern Chemicals of concern for each medium shall be identified in accordance with the procedure described in these comments A narrative shall be supplied describing the selection process of potential contaminants of concern Such factors as potential contaminant releases potential routes and magnitude of exposure environmental fate and transport (mobility persistence and bioaccumulation) toxicity and exceedance of promulgated standards should be carefully evaluated

2 Exposure Assessment I

The purpose of this section is to identifY all plausible present and potential future exposure scenarios and pathways in accordance with Region I Guidance and RAGS Identification of complete exposure pathways includes a source transport medium exposure route and receptor Present and future potential exposures to site contaminants must be identified Also socioeconomic status of potential human receptors and sensitive human populations must be identified (Note Present and future potential exposures are closely related to land use EPA - New England RCRA Corrective Action follows the CERCLA policy on land use TIle default assumption is future residential land use unless other scenarios are demonstrated as likely under the CERCLA policy and are approved by RCRA Corrective Action) This effort shall result in the development of a conceptual model for the facility Tables or flow charts are recommended as useful methods of presenting the possible exposure pathways

Narrative descriptions and summary tables of exposure scenarios shall be provided in this submittal The exposure scenarios for current and potential future land use shall include but not be limited to exposure parameters characteristic of an average (or central tendency) and a reasonable maximum exposure for all parameters In the absence of fully justifiable siteshyspecific values for exposure parameters values shall be taken from Standard Default Exposure Factors Supplemental Guidance to RAGS and the August 1994 Risk Update as first sources EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment as a second source followed by RAGS Part A See Sample Table 2

3 Exposure Assessment II

The purpose of the exposure assessment is to estimate a range of possible exposures which may result from actual or threatened releases of hazardous substances from the site The average and reasonable maximum exposure levels which are to be characterized are defined by the manner in which the contaminant concentration is coupled with average (or central tendency) and reasonable maximum exposure parameters developed for each exposure scenano

B-2

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

The resulting exposure levels (to be referred to as the central tendency or average and the reasonable maximum exposure levels--see the August 1994 Risk Update) shall be presented in the draft and revised in the final risk assessment report if additional validated data is received The fonnat of the exposure point concentrations and exposnre dose levels shall be presented in narrative form and tables See Sample Table 2

4 Dose-Response Evaluation

The objective of this component is to identifY the nature and probability of adverse health effects which could be expected to result from exposure to the contaminants of concern Carcinogenic and noncarcinogenic effects are characterized independently The doseshyresponse evaluation for possible carcinogenic effects is described by the cancer slope factor (CSF) while for noncarcinogenic effects the reference dose (RfD) or other suitable health based criteria should be used Agency verified dose-response criteria obtained from IRIS should preferentially be used followed by HEAST

The Facility shall provide a dose-response evaluation consistent with the EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part I Public Health Risk Assessment Chapter 3

5 Risk Characterization

Risk characterization integrates the information developed during the toxicity assessment (hazard identification and dose response evaluation) and the exposure assessment to quantifY the risks from the site for each exposure pathway Exposure pathways are then summed as appropriate following Region I Guidance and RAGS Presentation of the risk characterization shall be in the form of tables which separately summarize the noncarcinogenic and carcinogenic health risk The format for the tables that shall be used are attached See Sample Tables 3 and 4

6 Uncertainties and Limitations

11is section shall address the uncertainties and limitations of the analysis It shall clearly address the major limitations sources of uncertainty and if supportable provide an indication as to whether they have resulted in an over- or under-estimation of the risk

Final Human Health Risk Assessment Report

TIe final Healtll and Environmental Risk Assessment document shall be submitted after the completion and acceptance of the draft described above The Facility shall incorporate into the final document any comments received from the Agency on the draft In addition any newly acquired validated data shall be incorporated into the final document The format of this report shall conform to the chapters and sections as follows

A Final Human Health Risk Assessment Report

10 IntroductionIHazard Identification 11 Site description and history

B-3

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

12 Site-specific objectives of risk assessment 13 CurrentlFuture land use and potentially exposed populations 14 Nature and extent of contamination 15 Selection of potential contaminants of concern 16 Fate and transport

20 Exposure Assessment 21 Exposure pathwaysconceptual model 22 Quantification of exposure 23 Identification of Uncertainties

30 Dose Response Evaluation 31 Criteria for carcinogenic effects 32 Criteria for noncarcinogenic effects 33 Uncertainties related to toxicity infonnation

40 rusk Characterization 41 Current land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables) 42 Future land-use narrative with separate tables for carcinogenic and noncarcinogenic

risks summed by pathway (see sample tables)

50 UncertaintyLimitations

60 References

70 Appendices 71 Documentationdata 72 Toxicity profiles for contaminants of concern

B-4

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Chemicals of Concern Average Concentration

(mgl)

Benzene 2

Chloroform 8

Chromium 13

11 Dich1oroethane 98

12 Dich1oroethane 1

Vinyl Chloride NO (2)

NO =Not Detected 0 =Detection Limit Include data qualifiers (Table for illustrative pmposes only)

SAMPLE TABLE 1

SUMMARY OF CONTAMINANTS IN GROUND WATER

Maximum Detection

(mgl)

Location of Maximum

Frequency of Detection

374(J) MW-11 10- 20

227

171 MW-7 50 shy 60

327

50 MW-11 10- 20

6119

1560 MW-10b 50- 60

927

15 MW-10b 30- 40

927

ND (2) - 0127

Regulatory Criteria Criteria Exceedance

Smgll 1

100 mgl shy(NIPDWR)

50 mgl shy(NIPDWR)

NIA shy

5 mgl 2

2MCL shy

B - 5

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

SAMPLE TABLE 2

EXPOSURE PATHWAY SUMMARY

EXPOSURE PA1HWAY

GROUND WATER

Ingestion

Inhalation

Dennal Absorption

SOILS

Incidental Ingestion

Denual Absorption

Inhalation

SURFACE WATER

Incidental Ingestion

Dennal Absorption

SEDIMENT

Incidental Ingestion

Dennal Absorption

Notes X = Quantitative Analysis Q = Qualitative Analysis NA = Not Applicable

(Table for illustrative purposes only)

CURRENT SITE CONDITIONS

NA

NA

NA

X

X

Q

X

X

X

X

FUTURE SITE DEVELOPMENT

X

Q

Q

X

X

Q

X

X

X

X

B-6

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

SAMPLE TABLE 3

Risk Characterization Carcinogenic Risks For The Possible Future Ingestion

Of Ground Water

Chemicals of Concern Concentration (mgll)

avg rna

Cancer Potency Factor mgkgdmiddotJ

Weight of Evidence

Exposure Factor lkgd

Risk Estimate Average

Risk Estimate Reasonable Maximum

Chloroform 8 171 6lE-03 B2 29E-02 IJE-06 3OE-OS

I I Dichloroethane 98 1560 9IE-02 B2 29E-02 2SE-03 4IE-03

12 Dichloroethane I IS 9IE-02 B2 29E-02 3lE-06 38E-OS

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

SUM 3E-04 4E-03

(Table for illustrative purposes only) (differences due to rounding)

B-7

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

SAMPLE TABLE 4

Contaminants of Concern

RISK CHARACTERIZATION NONCARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION

OF GROUND WATER

Concentration (mgl) Reference Dose mgkgd

avg max Exposure Factor lkgd

Hazard Index Average

HI Reasonshyable Maximum Toxicity

Endpoint

Acetone 44 374 11E-OI 29E-02 13E-02 11E-02 increased liver amp kidney weight

Chloroform 8 171 10E-02 29E-02 22E-02 49E-OI liver lesions

Chromium 13 50 50E-03 29E-02 77E-02 29E-02 hepatotoxi-city

Hazard Index Sums Average Maximum Exposure

Liver Effects IE-O I 9E-Ol

Kidney Effects I E-02 IE-Ol

Exposure Factor 2 liters of ground water per day 70 kg person for 70 years

(Table for illustrative purposes only--differenccs due to rounding)

B - 8

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

ATTACHMENT C

Uncertainties Associated with Endocrine Disruptors

PCBs have been implicated as potential endocrine disruptors At this time the available information is not sufficient to determine whether PCBs are likely to affect human endocrine systems or to quantifY potential effects in a risk characterization The existence of limited information suggesting that PCBs may be endocrine disruptors along with the lack of information needed to confirm or quantifY such effects results in a degree of uncertainty about the conclusions of the risk assessment

TIle term endocrine disruptors applies to any number of a broad class of chemical compounds with the ability to perturb or interfere with the finely-tuned endocrine system that is fundamental to normal function and homeostasis in cells tissues and organisms Examples of chemicals suspected of being endocrine disruptors are the pesticides atrazine DDT endosulfan chlordane heptachlor 245-T and 24-0 Other chemicals suspected of being endocrine disruptors are PCBs dioxins and furans

TIle current concern about endocrine disruptors stems from a body of diverse historical information and more recent findings which have been integrated into a working hypothesis TIle central theme of the hypothesis is that exposure to exogenous homlOne-mimetic agents that interfere with the production release transport metabolism receptor binding action or elimination of natural bloodshyborne hormones and ligands can potentially lead to adverse health effects including effects on reproductive function development neurotoxicity and immunofunction

The data that have contributed to this working hypothesis stem from a number of different disciplines These include wildlife reproduction (feminization of birds alligators and certain terrestrial mammals) wildlife population ecology (popUlation declines) human reproductive physiology (decreased spenn count in males in industrialized nations) epidemiology (observed increases in breast cancer in industrialized nations) molecular biology (receptor-mediated mode of action data) and endocrinology (increased understanding of mechanisms of homlOne regulation and impacts of perturbations) TIlese findings serve as a basis for further experimentation to determine whether the fundanlental hypothesis is correct and if so to what extent

Wildlife studies have established a link between exposure to some environmental chemicals and endocrine disruption The relevance of reproductive effects observed in various wildlife species to potential reproductive effects in humans has not been established Furthermore while PCBs have been implicated reproductive effects have not been linked definitively to any PCB mixture or to any particular component of PCB mixtures

TIle tentative identification of chemicals including PCBs which could qualifY as endocrine disruptors is particularly problematic for the process of risk assessment for the following reasons (1) reliance on limited and in some cases conflicting empirical data to support the designation of specific chemicals as endocrine disruptors (2) lack of a clear structure-activity relationship among the diverse group of chemicals considered to be endocrine disruptors (3) lack of unifying doseshyresponse relationships among the diverse group of chemicals and (4) existence of multiple modes of action for chemicals currently considered to be endocrine disruptors

C - I

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

Given the current limited state-of-the~science it is premature to attempt to evaluate the potential human health risks from exposure to chemicals from the standpoint of endocrine disruption TIlerefore the US EPA has not yet developed a methodology for the quantitative assessment of risks due to exposures to potential endocrine disruptors

c - 2

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

ATTACHMENT D

COMMENTS FROM CONNECTICUT DEPARTMENT OF PUBLIC HEALTH ON

PROPOSAL FOR HUMAN HEALTH RISK ASSESSMENT OF THE HOUSATONIC RIVER

C - 3

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

bull

MEMORANDUM

TO TRACI lOTI CTDEP BUREAU OF WATER MANAGEMENT

THRU MARY LOU FLEISSNER DIREcrOR crDPHfEEOH ~ J1 ~

FROM GARY GINSBERGBRIAN TOAL CTDPHlEEOH

DATE May 3 1996

RE CHEMRISK PROPOSAL FOR PCBS RISK ASSESSMENT

In response to your memo dated March 6 1996 EEOH has reviewed the ChemRisk document titled Proposal for Human Health Risk Assessment of the Housatonic River dated 211496 The following co~ents on the proposed risk-assessment approach fOCus upon issues that would impact the assessment of PCB exposure and risk from recreational fishing in Connecticut Please let us know if you need additional input on this risk assessment protocol (509-7742)

Exposure Assessment

I Section 621 Identification of Exposure Points - ChemRisk intends to use an iterative risk-based approach to determine the spatial reaches of river where specific exposure scenarios are worth running The assumption is that water and sediment quality improven the downstream direction such that ifrisks are not elevated for a given scenario in the most proximal reach then risks will also not be elevated further downstream To support this the risk assessment should provide summary data showing trends in media (sediment soil water fish) concentrations of PCBs as distance downstream increases This should include Connecticut portions of the river

2 Recreational Fishing - Page 6-10 The Connecticut portion recreational fishing scenario is proposed to involve 2 sub-scenarios The first assumes that no fish are eaten and that exposure is only from contact with water and soilsediment The second assumes fish are eaten in spite of the Connecticut fish consumption advisory These scenarios misrepresent the Connecticut fish consumption advisory in that the advisory doesnt warn against eating all Housatonic River fish In particular yellow perch from the Bulls Bridge area yellow perch and sunfish from Lake Lillinonall and yellow perch white perch and sunfish from Lake Zoar are exempted from the advisory Further for Lake Housatonic (in SheltonlDerbySeymour) do not eat advice is provided only for carp and eels

We recommend a modification of the recreational fishing scenarios to include the following exposures

- -- ----- ---~- -~--- --~-----

Recreational Fishing in CT Scenario A anglers follow CT advisory with anglerfamily receiving PCB fish ingestion exposure based upon the concentrations for fish not in advisory + angler exposure from water amp soilsediment contact Assessment should be specific to individual fish species and to discrete sections ofriver or impoundments (Lake Zoar Lake Lillinonah Lake Housatonic) to the extent possible and practical

Recreational Fishing in CT Scenario B anglers do not follow CT advisory with anglerfamily receiving PCB fish ingestion exposure to all species +angler exposure

from water amp soiiJsediment contact ~~panite sa1culations shotlg1~J~~_~_r_lCh species and river sectionimpoundment for which suitable PCBs in fish data are av~Uable In this way theassessnlent coUfd-address~g~rs whodonHollow the advisory and who may concentrate on specific fish and sections of the Housatonic River in Connecticut

3 Exposure Duration (page 6-25) - The exposure duration (nUmber of years of exposure) for the recreational fishing scenario is not defined

4 Fish Consumption Rate (Page 6-37) - Tne proposed approach utilizes a fish consumption rate of 64 glday which is based upon a survey of recreational anglers conducted in Maine This value is low based upon fish consumption data compiled in USEPA 1995 (Guiregnc~poundOI A~~lSilg Che~al g2lffimination Data for use in Fish Adyisorie~YQIme ill Risk Management) and in Co~ticut(ioaI--1987) In the USEPA compilation-meaD-fish consumption rates among the sportfishing population ranged from 77 ((1448 gday with values for subsistence fishers Gonsiderably higher Most of these values pertain to recreatioually caught (as opposed to commercially obtained) fish A fish consumption survey of 203 Conne~ticut anglers indicated an average rate of U15 gld of recreation ally caught fish Chemrlsks methodology should ta1ce into consideration the data compiled by USEP A and that obtained in Connecticut to modifY the parameter estimate for daily fish consumption Further the potential for subsistence fishing to occur along portions 0f the Housatonic River should be addressepshythrough a subsistence fishing scenario which is in addition to the 2 recreational scenarios outlined above The A and B recreational scenarios should be adapted to subsistence fishers based upon a considerably higher fishing frequency and consumption rate

According to Table 6-5 the fish consumption rate of 64 gld is to be applied equally to children and adults This assumption is not justified and would appear to be a major oversimplification For example USEP A has estimated the average fish meal size for children under 4 to be 3 ounces which is considerably less than the default adult fish meal size of 8 ounces (USEPA 1995 cited above) Further the state of Minnesota has pro-rated fish consumption according to body weight (Minnesota Dept of Health 199 [ Criteria Used to Issue Fish Consumption Advice)

~~~~~~~~~~~~~~~-~--~~~~~~~~-~~~-~----~~~-----~

5 Cooking Losses of PCBs from Fish (page 6-38) - Tile proposed approach is to assume a 44 loss in PCB content offish due to cooking This is based upon a weightedshyaveraging approach which takes into account data describing how many people use various cooking methods and estimates ofPCB reduction for each method As noted in the ChemRisk proposal cooking-related reductions in PCBs are highly variable In fact USEPA 1995 (cited above) Indicates that some studies for a particular cooking method (eg frying) show a substantial loss in PCB concentration while others show no reduction or even an increase The variability apparently depends on fish species filletingtrimming techniques method of reporting the data and a host ofuncontrolled factors Given this high degree of varIability und~ controlled laboratory conditions the ability to ascribe a percentage cooking loss that is generally applicable to the home environment is very questionable

Instead of expressing cooking loss on a concentration basis Sherer and Price relied only upon the dara describing cooking loss on a total mass basis (Qual Assur Good Pract Reg Law 2 396-407 1993) Even when expressed this way at least one study showed an increase in PCB amount post-cooking which may be due to increased extractibiJity ofPCBs from fish tissue resulting from thermal decomposition of the tissue (Sherer and Price 1993) Such a thermal process might also affect (increase) the bioavailability ofPCBs from fish relative to the bioavailability of PCBs from rodent diets used in toxicology studies This adds to the uncertainty in attempting to ascribe a decrease in PCB exposure and rsk due Ie cooking losses

We reco=end that the rottntial cooking losses not be quantitatile1y factored ino the risk asStssment but instead be used in a qualitative discussion of the calculated risks This approach should highlight the variability and uncerrainty surrounding cookingshyrelated reductions in PCBs when discussing the potential benefits of this factor

Dose~Response Assessment

1 Section5221 (page 5-7) ~ This section states that the rype of PCB mixture found at the site is Aroclor 1260 with an RID based upon Aroelor 1254 not directly applicable However A 1254 is a major contaminant of fish from Connecticut portions of the Housatonic River and in some cases the AI254 concentration exceeds the A 1260 concentration in fish tissue (Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River) These dara should be considered when discussing the applicability of the A1254 RID to the fish consumption scenario in Connecticut

2 The proposal suggests the use of a PCB cancer potency factor that is well below the current IRIS value based upon a recent EPA draft reassessment and ChemRisks oWll analysis EEOHconsiders the IRIS potency factor valid until formal notification otherwise from USEPA The fish consumption cancer risk assessment should thus utilize the IRIS potency value an alternative assessment using a modified potency value consistent with EPAs draft reassessment can also be presented

~

Risk Charactcri mon

1 Section 7312 Benchmark for Cumulative Cancer Risks - The use of IE-05 as the benchmark for site-wide cancer risk is consistent with recent CTDEP cleanup criteria However these criteria also stipulate that individual chemicals should contribute no more than 1E-06 risk to the overall risk The risk assessment should take this approach into consideration when judging the degree ofrisk associated with the fishing scenario in Connecticut

1. barcodetext SDMS DocID 124631
2. barcode 124631

~~~~~~~~~~~~~~~-~--~~~~~~~~-~~~-~----~~~-----~

5 Cooking Losses of PCBs from Fish (page 6-38) - Tile proposed approach is to assume a 44 loss in PCB content offish due to cooking This is based upon a weightedshyaveraging approach which takes into account data describing how many people use various cooking methods and estimates ofPCB reduction for each method As noted in the ChemRisk proposal cooking-related reductions in PCBs are highly variable In fact USEPA 1995 (cited above) Indicates that some studies for a particular cooking method (eg frying) show a substantial loss in PCB concentration while others show no reduction or even an increase The variability apparently depends on fish species filletingtrimming techniques method of reporting the data and a host ofuncontrolled factors Given this high degree of varIability und~ controlled laboratory conditions the ability to ascribe a percentage cooking loss that is generally applicable to the home environment is very questionable

Instead of expressing cooking loss on a concentration basis Sherer and Price relied only upon the dara describing cooking loss on a total mass basis (Qual Assur Good Pract Reg Law 2 396-407 1993) Even when expressed this way at least one study showed an increase in PCB amount post-cooking which may be due to increased extractibiJity ofPCBs from fish tissue resulting from thermal decomposition of the tissue (Sherer and Price 1993) Such a thermal process might also affect (increase) the bioavailability ofPCBs from fish relative to the bioavailability of PCBs from rodent diets used in toxicology studies This adds to the uncertainty in attempting to ascribe a decrease in PCB exposure and rsk due Ie cooking losses

We reco=end that the rottntial cooking losses not be quantitatile1y factored ino the risk asStssment but instead be used in a qualitative discussion of the calculated risks This approach should highlight the variability and uncerrainty surrounding cookingshyrelated reductions in PCBs when discussing the potential benefits of this factor

Dose~Response Assessment

1 Section5221 (page 5-7) ~ This section states that the rype of PCB mixture found at the site is Aroclor 1260 with an RID based upon Aroelor 1254 not directly applicable However A 1254 is a major contaminant of fish from Connecticut portions of the Housatonic River and in some cases the AI254 concentration exceeds the A 1260 concentration in fish tissue (Interim Report on 1990 Analyses of PCBs in Fishes from the Housatonic River) These dara should be considered when discussing the applicability of the A1254 RID to the fish consumption scenario in Connecticut

2 The proposal suggests the use of a PCB cancer potency factor that is well below the current IRIS value based upon a recent EPA draft reassessment and ChemRisks oWll analysis EEOHconsiders the IRIS potency factor valid until formal notification otherwise from USEPA The fish consumption cancer risk assessment should thus utilize the IRIS potency value an alternative assessment using a modified potency value consistent with EPAs draft reassessment can also be presented

~

Risk Charactcri mon

1 Section 7312 Benchmark for Cumulative Cancer Risks - The use of IE-05 as the benchmark for site-wide cancer risk is consistent with recent CTDEP cleanup criteria However these criteria also stipulate that individual chemicals should contribute no more than 1E-06 risk to the overall risk The risk assessment should take this approach into consideration when judging the degree ofrisk associated with the fishing scenario in Connecticut

1. barcodetext SDMS DocID 124631
2. barcode 124631

~

Risk Charactcri mon

1 Section 7312 Benchmark for Cumulative Cancer Risks - The use of IE-05 as the benchmark for site-wide cancer risk is consistent with recent CTDEP cleanup criteria However these criteria also stipulate that individual chemicals should contribute no more than 1E-06 risk to the overall risk The risk assessment should take this approach into consideration when judging the degree ofrisk associated with the fishing scenario in Connecticut

1. barcodetext SDMS DocID 124631
2. barcode 124631