Five-Year Review Report · Table 4-2, Summary of the Comparison of Analytical results with the...

EPJl, Region 5 R

IUI"111I118181;01;Ctr.

323194

Five-Year Review Report

Third Five-Year Review Report

for

MIDCO I

Gary

Lake County, Indiana

March 2009

PREPARED BY:

Region 5, U.S. Environmental Protection Agency Chicago, Illinois

Approved by: Date:

Richard Karl, Director Superfund Division

[This page intentionally left blank.]

Five-year Review Report - 2


Table of Contents

List of Acronynls 6

Executive SUffilnary 9

Five-Year Review Summary Form 11

I. Introduction 13

II. Site Chronology 14

III. Background 15 Physical Characteristics " 15 Land and Resource Use 16 History of C·ontamination 16 Initial R.esponse 16 Basis for Taking Action 16

IV. Remedial Actions 18 Remedy Selection 18 Remedy Implementation 20 Institutional Controls (lCs) and Access Restrictions 35 O&M C:osts 37

V. Progress Since the Last Five-Year Review 37

VI. Five-Year Review Process , 41 Administrative Components .40 Community Notification and Involvement .40 Document and Data Review 42 Site Inspections 42 Intervit:ws 42

VII. Technical Assessment .42 Question A: Is the remedy functioning as intended by the decision documents? .42 Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives (RAOs) used at the time of the remedy selection still valid? .43 Question C: Has any other information come to light that could call into question the protectiveness of the remedy? , .47 Technical Assessment Summary 47

VIII. Issues 48


IX. Recommendations and Follow-up Actions .49

X. Protectiveness Statement(s) .49

XI. Next Review 50

Tables Table I - Chronology of Past Events Midco I Table 2 - Future Schedule Midco I Table 3 - Cleanup and Perfonnance Requirements for Midco I Table 4 - EPA, Weston and IDEM Inspections of Midco I from April2004-December

2008 Table 5: Comparison ofVOCs (ugll) Exceeding GWCALs Outside Barrier Wall in 2004,

2005 and 2008 Table 6: Comparison of Benzene, Cis-l ,2-Dichloroethylene, 1,2-Dichloroethane,

methylene chloride, Trichloroethylene, and Vinyl Chloride Concentrations (ugll) in EW3 and EW4 in 2004, 2005, and 2008

Table 7: Comparison 2004 and 2008 of Frequency of Detections and Maximum detections of Inorganic Contaminants Exceeding GWCALs

Table 8: Summary of Semivolatile Organic Compound, Pesticide, and PAH detections exceeding a GWCAL in 2005

Table 9 - Actions Taken Since the Last Five-Year Review Table 10- Issues Table 11 - Recommendations and Follow-up Actions

Attachments Figure 1, Well and Piezometer Locations Midco I Site, 2005 Annual Ground Water Monitoring Report, ENVIRON, May 2006

Figure 1, Site Location Map, Midco I Site

Table 1-1, List of Parameters Analyzed and Project-Specific Quantitation Limits Midco I and II Sites, 2005 Ground Water Monitoring Report.

Figure 4, (Figure 3-1, Monitoring Well Network), Second Five Year Review Reportfor MidcoI, EPA, May 17,2004.

Figure 1-5, Capture Zone Analysis Recalibrated Model, May 9, 2005 ENVIRON letter re: Revised 2005 Capture Zone Evaluation

Table 4-2, Summary of the Comparison of Analytical results with the Clean-Up Action Levels, 2005 Annual Ground Water Monitoring Report.


Table 4-2, Summary of Comparison of Analytical Results with the Cleanup A.ction Levels, 2008 Annual Ground Water Monitoring Report, ENVIRON, October 2008.

Figure 2, SVE System Piping L~yout, Construction Completion Reportfor the Soil Vapor Extraction System, ENVIRON, November 2006.

Pictures taken by ENVIRON on April 21, 2008 showing the condition of the fence enclosing the sediment area and monitoring wells northeast of Midco I.

Notice in Post-Tribune, September 7,2008.

Update 6 to the Midco I Administrative Record

Table 3··1, Parameter-Specific Cleanup-Up Action Levels and Associated Parameters, 2005 Annual Monitoring Report


List of Acronyms

AWQC: EPA Ambient Water Quality Criteria

cm/sec: centimeters per second (a unit for hydraulic conductivity)

Consent Decree: Consent Decree for Civil Action No. H 79-556, United States of America vs Midwest Solvent Recovery, Inc., et al. (Defendants); American Can Company, Inc., et al. (Third Party Defendants); vs Accutronics, et al. (Third Party Defendants), which was filed in the United States District Court in Hammond, Indiana on July 23, 1992.

CR: cumulative, incremental lifetime cancer risk

ENVIRON: ENVIRON International Corporation, a consultant for the MRC from June 2000 to the present

EPA: United States Environmental Protection Agency

ERM: Environmental Resources Management, a consultant for the MRC from approximately 1987 to September 2002

ESD: Explanation of Significant Differences (EPA document to describe and explain changes to the ROD that do not require an amendment)

ESD#1 Explanation of Significant Differences dated 1 /9196 (EPA document to change MAC and GWCAL for 1, I-dichloroethane)

ESD#2 Explanation of Significant Differences dated 11 12/99 to change the MAC and GWCALs for certain polyaromatic hydrocarbons

ESD#3 Explanation of Significant Differences dated 9/30104 primarily to change soil cleanup components

GC gas chromatograph

gpm gallons per minute

GWCALs groundwater cleanup action levels (these are concentrations of contaminants required to be achieved at the end of the groundwater cleanup)

HBLs Health Based Levels used to evaluate requests to delist hazardous wastes under the Resource Conservation and Recovery Act (for groundwater HBLs were set


equal to the MCL or to the more stringent of CR = 10-6

water usage ifan MCL was not available)

HI cumulative incremental non-carcinogenic hazard index

ICs institutional controls

IDEM Indiana Department of Environmental Management

InDOT Indiana Department of Transportation

IRIS EPA's Integrated Risk Information System.

LEL Lower explosive limit

or HI =1.0 for residential

MACs maximum allowable concentrations (the treated groundwater must he less than these concentrations before being deep well injected)

MCLs Primary Maximum Contaminant Levels for drinking water from 40 CFR 121

mglkg milligrams per kilogram, a unit for contaminant concentration in soil, equal to parts per million

mgll milligrams per liter, a unit for contaminant concentration in groundwater, equal to parts per million

MRC Midco Remedial Corporation (a corporation formed by the Settling Defendants to the Midco I and Midco II Consent Decree for the purpose of implementing the requirements of the Consent Decree)

OMMCP Operation, Maintenance. Monitoring, and Closure Plan, ENVIRON, November 2006.

O&M operation and maintenance

pounds/hr pounds per hour

ppm parts per million

pSI pounds per square inch (a unit for compressive strength)

PAHs Polyaromatic hydrocarbons

PCBs Polychlorinated biphenyls


PID

PRO

QAPP

RCRA

RVFS

ROD

ROD Am

RPM

sediment/ soil CALs

SOW

SIS

SVE

SVOCs

TWSLs

ugll

UIC

UV/HP

VOCs

Weston

Photoionization detector

EPA, Region 9's preliminary remediation goals

Quality Assurance Project Plan

Resource Conservation and Recovery Act

Remedial Investigation/Feasibility Study

Record of Decision (EPA's official decision document). Unless otherwise noted, this refers to the 1989 ROD.

The 1992 Record of Decision Amendment

EPA Remedial Project Manager

sediment/soil cleanup action levels (required to be achieved in soil below sediments that are excavated)

Statement of Work, Appendix I to the Midco I and Midco II Consent Decree

solidification/stabilization

soil vapor extraction

semivolatile organic compounds

Region 3, tap water screening levels

micrograms per liter, a unit used to express the concentration of contaminants in groundwater and is equal to parts per billion in water

micrograms per cubic meter, a unit used to express concentration of contaminants in atr

EPA, Region 5's Underground Injection Control Branch

Ultraviolet/hydrogen peroxide

volatile organic compounds

Weston Solutions, Inc., EPA's oversight contractor


Executive Summary

The selected remedy for this industrial disposal site includes: access restrictions; deed restrictions; excavation of contaminated sediments and soil from sediment areas to achieve soil/sediment CALs, and consolidation of the excavated soil onto the source area; groundwater pump-and-treat and disposal via deep well injection to achieve the groundwater cleanup action levels (GWCALs); soil treatment by soil vapor extraction (SVE) after construction of a groundwater barrier wall and lowering the watE~r table by 12-15 feet within the source area to achieve at least a 97% reduction in voleltile organic compounds (VOCs); excavation or solidification/stabilization (S/S) of high metals and cyanide contaminated soils; and a site cover over the source area. The remedial actions are being implemented under a Consent Decree by a group of Settling Defendants, who have formed the Midco Remedial Corporation (MRC) to implement the remedy. The U.S. Environmental Protection Agency (EPA) and the Indiana Department of Environmental Management (IDEM) are overseeing implementation of thf3 remedy.

In 1993, the MRC excavated the upper 3 to 12 inches of contaminated sediments and soil from sediment areas, but contamination remains in the soils left in place. In 1994, the site fence was extended to enclose the sediment areas to restrict human access. Also in 1993, the MRC filed deed restrictions on a number of the properties. In 1994 and 1995, the MRC constructed the pump-and-treat and deep well injection system, which has been in operation since 1997. In 2003, the MRC constructed and started dewatering within the groundwater barrier wall. In 2005 - 2006 the MRC constructed the SVE system, which has been in operation since March 2006. In addition to continued O&M and monitoring of the pump-and-treat and deep well injection system, and the SVE system, the following active remedy components have not been completed: excavation of the high metals and cyanide contaminated soil, construction of the final site cover; and actions to address the remaining sediment area contamination.

The access restriction, groundwater pump-and-treat and deep well injection, and SVE portions of the remedy are functioning as intended in the ROD, including complying with air emission limitations and deep well injection requirements. The pump-and-treat system is adequately containing the contaminated groundwater, and there have been reductions in the concentrations of most groundwater contaminants. The SVE system has been very successful in removing a large quantity of VOCs from the source area soils. There is concern that contaminants remaining in the source area soil::; after completion of the SVE will have the potential to re-contaminate the groundwater. Although there are deed restrictions on some properties, the deed language and other institutional controls need to be updated, fully implemented, and monitored.

The toxicity factors and exposure assumptions for evaluating air emissions, and the treatment requirements prior to deep well injection are protective. During dl3sign of the final site cover, the final actions for the remaining contaminated sediments will be decided and toxicity factors for development of the soil/ sediment cleanup action levels


may also need to be reassessed. When shut-down of the pump-and-treat is requested, the groundwater cleanup action levels may need to be updated.

The remedy protects human health and the environment in the short term because: • Fencing, deed restrictions on some properties, and on-site staff prevent human

exposure to the contaminated groundwater, soils and sediments (a City of Gary Ordinance also prohibits residential usage of groundwater);

• Although wildlife can be exposed to the contaminants remaining in the sediment areas, the area affected is small, the value of the habitat is minor, and the contaminant concentrations may not exceed background; and

• Monitoring is being performed to assure that the SVE emissions comply with air emission limitations, and the thermal oxidizer is being maintained to treat the air emissions, if necessary.

In order for the remedy to be protective in the long-term, the following actions are needed:

• Continued restriction of access; • Continued O&M and monitoring of the pump-and-treat system to contain the

contaminated groundwater and attempt to achieve the GWCALs (Operable Unit #1);

• Continued O&M and monitoring of the SVE system (Operable Unit #2); • Excavation of high metals and cyanide contamination (Operable Unit #2); • Addressing potential for re-contamination of groundwater by contaminants

remaining within the barrier wall after discontinuation of the SVE, pump-andtreat, and excavation (Operable Unit #1);

• Consideration, and if necessary, evaluation of ecological risks and adjustment of the soil/sediment CALs during design of the site cover and final sediment excavation;

• completion of sediment excavation; • installation of the final site cover (Operable Unit #3); • update the GWCALs; and • full implementation and monitoring of ICs.


Five-Year Review Summary Form

SITE IDENTIFICATION

NPL status: X Final 0 Deleted 0 Other (specify)

Remediation status (choose all that apply): X Under Construction X Operating 0 Complete

Multiple OUs?* X YES 0 NO IConstruction completion date: NA _ / _ / _

Has site been put into reuse? 0 YES X NO

REVIEW STATUS

Lead agency: X EPA 0 State 0 Tribe 0 Other Federal Agency

Author name: Richard Boice

Author title: Environmental Engineer IAuthor affiliation: U.S. EPA

Review period:-- 5/ 17 / 2004 to 02/ / 2009

Date(s) of site inspection: 8 / 26/ 2008

Type of review: x Post-SARA o Pre-SARA o NPL-Removal only o Non-NPL Remedial Action Site o NPL StatefTribe-lead o Regional Discretion

Review number: 01 (first) 02 (second) X 3 (third) 0 Other (specify)

Triggering action: o Actual RA Onsite Construction at au #__ DActual RA Start at OU#__ o Construction Completion X Previous Five-Year Review Report o Other (specify;,

Triggering action date (from WasteLAN): 5/ 17/ 2004

Due date (five years after triggering action date): 5 / 17/ 2009 ~ ["aU" refers to operable Unit.] ** [Review period should correspond to the actual start and end dates of the Five-Year Review in WasteLAN.]


Five-Year Review Summary Form, cont'd. Issues: 1. Contamination from off-site may make it impossible for pump-and-treat system to achieve all GWCALs 2. GWCALs may not be protective 3. SedimenUsoils remaining in sediment excavation areas exceed CALs 4. SedimenUsoil CALs may not be protective 5. IC work not complete

Recommendations and Follow-up Actions: Issues 1 and 2: Evaluate and update GWCALs and other remedy revisions at the time of review of request to shut-down pump-and-treat. Issues 3 and 4: Evaluate soil/sediment CALs, and whether to cover or further excavate the sediments, during design for final site cover. Issue 5: Perform additionallC evaluation, as needed; File updated restrictive covenants for all necessary properties; work with City of Gary to assure notification of non-potable groundwater usage near Midco I; add IC monitoring to O&M plan.

Protectiveness Statement(s):

The remedy protects human health and the environment in the short term because: - Fencing, deed restrictions on some properties, and on-site staff prevent human exposure to the contaminated

groundwater and sediments ( a City of Gary ordinance also prohibits residential usage of groundwater); - Although wildlife can be exposed to the contaminants remaining in the sediment areas, the area affected is small,

the value of the habitat is minor, and the contaminant concentrations may not exceed background; - Monitoring is being performed to assure that SVE emissions comply with air emission limitations, and the thermal

oxidizer is being maintained to treat the air emissions, if necessary;

In order for the remedy to be protective in the long-term, the following actions are needed: - Continued access restrictions; - Continued O&M and monitoring of the pump-and-treat system to contain the contaminated groundwater and

attempt to achieve the GWCALs (Operable Unit 1); - Continued O&M and monitoring of the SVE system to achieve a 97% reduction and protect groundwater

(Operable Unit 2); - Excavation of high metals and cyanide contamination (Operable Unit 2); - Consideration, and if necessary, evaluation of ecological risks and update of the soil/sediment CALs during design

of the site cover and final sediment excavation; - Completion of sediment excavation; - Installation of the final site cover (Operable Unit 3); - Update the GWCALs; and - full implemention and monitoring of ICs.

Other Comments: None.

Date of last Regional review of Human Exposure Indicator (from WasteLAN): _9/28/2006__ Human Exposure Survey Status (from WasteLAN): _current human exposure under control__ Date of last Regional review of Groundwater Migration Indicator (from WasteLAN): _6/12/2007 Groundwater Migration Survey Status (from WasteLAN): _contaminated groundwater under control Ready for Reuse Determination Status (from WasteLAN): _NO _



I. Introduction

This report presents the methods, findings, conclusions, and recommendations of the third five-year review for the Midco I site located in Gary, Indiana. The purpose of this review is to evaluate implementation and performance of the remedial actions in order to determine whether or not the remedy is or will be protective of human health and the environment. The remedial action for the Site is expected to result in hazardous substances remaining above concentrations that would limit use and restrict exposure at the end of the remedial action. Therefore, a five-year review is required by statute.a

This report was prepared by Region 5 of the U. S. Environmental Protection Agency (EPA). This five-year review relied upon reports and evaluations performed by the following parties:

• Weston Solutions, Inc. (Weston), EPA's oversight contractor from 1985 through 2006;

• ENVIRON International Corporation (ENVIRON), a consultant for the Midco Remedial Corporation (MRC) from June 2000 through the present;

• Indiana Department of Environmental Management (IDEM); and • Subsurface Construction Corporation, Houston, Texas (for the underqround

injection well testing).

The following parties reviewed and provided comments on this report: ENVIRON; IDEM; LFR Inc., another consultant working for the MRC; the EPA Region ft, Underground Injection Control Branch (UIC); and the MRC, which represents a group of companies responsible for performance of the cleanup pursuant to the 199~~ Consent Decree with EPA and IDEM.

Work specifically on the third five-year review was initiated by the EPA Remedial Project Manager (RPM) on August 7, 2008, but oversight and evaluation of the remedial actions (which has included construction, operation and maintenance (O&M), and monitoring of a soil vapor extraction system (SVE), and O&M and monitoring of a pump-and-treat / deep well injection system) has been an ongoing process over the last five years. This oversight and evaluation has included periodic on-site inspections, and review of reports on design, O&M, and monitoring. This five-year review will be officially completed on the signature date of the report. This report will be placed in the Midco I Administrative Record file located at EPA's, Region 5 office at 77 W. Jackson Blvd., Chicaqo, Illinois;

a Section 121(c) of the Comprehensive Environmental Response Compensation and Liability Act. 42 U.S.c. ~ 9621 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act (SARA), and Section 300.430(~)(4)(ii) of the National Contingency Plan, require periodic review (at least once e\ery five years) for sites where hazardous substances, pollutants or contaminants will remain above levels that would allow unlimited use am'. umestricted exposure after completion of the remedial action.


and in the local document repository, which is located in the City of Gary Public Library.

II" SITE CHRONOLOGY

The following Table 1 provides a chronology of past events, and Table 2 provides the future schedule.

Table 1" Chrono ogy 0 f PtE t M"das yen s I co"

EVENTS THROUGH REMEDY SELECTION

Midco I site used for industrial waste storage, recycling, and disposal

DATES

1973 -1979

EPA installed a fence around the site

EPA removed all surface wastes (including thousands of drums and a number of tanks), removed the top 6 - 12 inches of contaminated soil), and placed clay soil over site.

EPA placed Midco I on the National Priorities List

Settling Defendants conducted Remedial Investigation/Feasibility Study (RI/FS)

6/81

2/82 - 7/82

9/8/83

1985-1989

EPA issued Record of Decision (ROD)

EPA issued ROD Amendment (ROD Am)

EPA, the State of Indiana and Settling Defendants entered into an agreement on the final remedial actions in a Consent Decree. The generator Settling Defendants formed the MRC to carry out the remedial actions.

EVENTS FOR GROUNDWATER REMEDY

MRC designed, constructed and tested the groundwater pump-and-treat / deep well injection system

MRC operated pump-and-treat I deep well injection system

EPA approved Five-Year Underground Injection Well Re-Application Package.

6/30 I 89

4 113/92

6/23/92

1992 -1996

1 / 97 -present

5/7 I 98

EPA issued first Five-Year Review Report

MRC constructed an expansion to pump-and-treat system to improve groundwater capture

EPA issued Second Five- Year Review Report

EPA approved the second underqround iniection re-application

EVENTS FOR SOIL REMEDY

MRC and EPA performed SIS treatability studies

MRC performed partial sediment excavation and on-site containment

10/29/98

2001

5/17 / 04

6 I 28 / 06

1992 -1/ 97

8/93 -10/93

MRC planned and performed treatability testing for chemical oxidation 2000 - 2001


MRC performed additional investigations, evaluation of alternatives, and designed groundwater barrier wall

2002 -2003

MRC constructed groundwater barrier wall, and initiated dewatering within barrier wall 11 - 12/03

EPA issued ESD#3, which included: construction of the groundwater barrier wall around the source area; performance of more complete SVE treatment by performing SVE following lowering the water table within a groundwater barrier wall; reduction of soil solidification/stabilization requirements; and addition of the option of excavation as an alternative to soil solidification/stabilization.

9/30/04

MRC designed the SVE system 2003 - 2005

MRC constructed and tested SVE system 3/05 2 / 06

MRC operated SVE system 3/06

present

EPA approved shut-down of thermal oxidizer 8/6/08

Table 2: Future Schedule Midco I

MRC will continue to dewater within the barrier wall and operate SVE, and will update ICs

Present -December 2009

MRC will excavate high metals and cyanide contaminated soil and dispose offsite (or treat by SIS), evaluate soil/sediment CALs as necessary, complete soil/sediment excavation, construct final site cover, and submit a request to shutdown the pump-and-treat system

2010

MRC will subm It updated underground injection Well reapplication 12/28/13 MRC will contirue to operate the pump-and-treat and deep well injection system, and monitor groundwater and ICs

Presel1t -Undetermined

III. Background

Physical Characteristics

The Midco I source area occupies approximately four acres located at 7400 West 15th

Avenue, Gary, Indiana, but the fence has been extended to enclose approximately seven acres including the groundwater treatment plant, and the contaminatE~d sediment areas (see attached Figure 1, Well and Piezometer Locations, 2005 Annual Ground Water Monitoring Report, ENVIRON, May 2006). Midco I is bordered on thE~ west by an Indiana Department of Transportation (InDOT) storage facility, on the north I:)y remnants of the original ridge and swale topography, on the east by cut-and-fill land that is now being used by a concrete recycling operation, and on the south by small business buildings (see attached Figure 1, Site Location Map). Midco I is approximately 3.8 miles south of Lake Michigan, and lies midway between the Grand Calumet River and the Little Calumet River. The Calumet aquifer is approximately 30 feet thick at Midco I and is underlain by a 110 foot thick sequence of silty clay, and silt loam. If no actions were


taken, the Midco I contaminated groundwater could eventually vent to either to wetlands north of the site or to the Grand Calumet River.

Land and Resource Use

Midco I is in an area of mixed use for commerce and light industry. It is within 1,500 feet of a residential neighborhood in Hammond, Indiana and within 3,000 feet of a residential neighborhood in Gary, Indiana. There are huge piles of concrete debris on property east of Midco I. On a conceptual master plan, the City of Gary has designated Midco I as part of a Route 912 Industrial Park, and has also been considered part of a Gary - Chicago Airport Development Zone. The Calumet aquifer is little used because the predominant source of residential and industrial water in the Midco I area is Lake Michigan. In an Ordinance dated September 20,2007, the City of Gary prohibited use of water from the Calumet aquifer as a potable water source.

History of Contamination

During its usage for industrial waste storage, recycling, and disposal, thousands of drums and some tanks of wastes were haphazardly stored on the site. In December 1976, a large fire destroyed an estimated 14,000 drums containing chemical wastes and resulted in more spillage. An estimated 14,000 additional drums of waste were brought onto the site between 1977 and 1979.

Initial Response

Early Court actions to require cleanup actions by the owner/operators were ineffective. In June 1981, EPA installed a fence around Midco I. From January through July 1982, EPA conducted removal and off-site disposal of surficial wastes at Midco I. This action included: removal of 7,000 cubic yards of crushed drums; 84,000 gallons of solvents; 5,600 gallons of acids; 13,500 gallons of bases; 56,500 gallons of inert wastes; 940 drums of flammable solids; 170 lab packs; and 7,200 cubic yards of soil (the top 6 inches to 1 foot). It also included placing 6 to 12 inches of clay soil over most of Midco I.

Midco I was placed on the National Priorities List in December 1982. A group of generators, who later formed the MRC, conducted the RI/FS from 1985 through 1989. EPA issued a Record of Decision (ROD) in June 1989.

Basis for Taking Action

The RI included evaluation of the hydrogeology, and extensive sampling of groundwater, source area subsurface soils, and surface sediments in surrounding wetlands. The RI demonstrated that the source area soils, and the groundwater near the site were highly contaminated, and presented a significant human health risk in case of future residential usage of the site, and to off-site property owners, and to biota in the


vicinity of the site. It was possible that continued off-site migration of contamination in groundwater would eventually reach downgradient residential wells.

Groundwater contamination exceeded the current Safe Drinking Water Act, Primary Maximum Contaminant Levels (MCLs) for the following contaminants:

benzene antimony bis(2-ethylhexyl)phthalate 1,2-dichloroethane arsenic lindane 1,1-dichloroethylene barium pentachloroplhenol methylene chloride chromium ethylbenzene cadmium tetrachloroethylene cyanide toluene lead trans-1,2-dichloroethylene selenium 1,1,1-trichloroethane thallium trichloroethylene trihalomethanes vinyl chloride xylene

Other contaminants of concern identified from the RI included: acetone copper butylbenzylphthalate 2-butanone iron chlordane bis(2-chloroethyl)ether nickel cresol chlorobenzene zinc di-n-butylphthalate chloroethane mercury dieldrin chloroform manganese diethylphthalate 1,1-dichloroethane vanadium isophorone 4-methyl-2-pentanone phenol 2-hexanone PAHs

PCBs di-n-octylphthalate endrin aldrin

An unanticipated finding was that the aquifer in the vicinity of Midco I is highly saline primarily due to sodium chloride. Chloride is detected as high as 15,000 milligrams per liter (mg/I) in groundwater below the site. It appears that most of the salinity was caused by groundwater migration from the InDOT salt storage facility, which bounds Midco I on the west. For additional details on the RI results see the Secone! Five-Year Review Report.


IV. Remedial Actions

Remedy Selection

Remedial Objectives: The remedial objectives used to select the remedial action in the 1989 ROD as revised by the 1992 ROD Amendment and three ESDs included:

• Eliminate direct contract threat from contaminated source area soil and sediments;

• Treat the principal threat in soil to substantially reduce the threat of groundwater contamination and the direct contact threat;

• Prevent off-site migration of contamination in groundwater; • Assure that contaminants do not adversely affect biota; and • Cleanup groundwater.

ROD Requirements: The 1989 ROD as amended by the 1992 ROD Amendment and revised by ESD#3, provides for the following remedy components:

• Excavation of contaminated sediments and underlying soils in defined wetland areas to achieve cleanup action levels (soil/sediment CALs) and consolidation on Midco I;

• Construction, O&M and monitoring of a groundwater pump-and-treat system to contain contaminated groundwater, and to achieve groundwater cleanup action levels (GWCALs);

• Construction, O&M and monitoring of a deep underground injection well for disposal of the contaminated groundwater following treatment;

• Construction of a groundwater barrier wall around the source area and pumping groundwater within the barrier wall to lower the water table;

• Treatment of contaminated soil within the groundwater barrier wall by SVE to achieve at least a 97% reduction in VOCs;

• Excavation or solidification/stabilization of the soil most highly contaminated by metals and cyanide; and

• Construction of a final cover, access restrictions, deed restrictions and monitoring.

Table 3 provides a summary of the cleanup performance requirements applying to each of these remedy components, and the source of those requirements:


t f MOdTable 3 - CIeanup an d P erformance ReQulremen s or I co

Component

Access

Restrictive Covenants

Sediment and soil excavation

Groundwater pump-and-treat

Deep well

Groundwater barrier wall

I I

Lowering water table by pumping within barrier wall

SVE I

Applicability Performance Requirements (source)

Site access Six foot chain link fence with 3-strand barbed wire around site, and warning signs (1989 ROD)

Property transactions

Excavation in defined sediment areas is required until CALs are met

Extent of groundwater capture

Pump-and-treat must continue until groundwater is less than GWCALs unless it is determined to be technically impracticable

The deep well must be located, constructed, tested, monitored and operated to meet requirements

The extracted groundwater must be less than these concentrations before being injected

Remedy component (1989 ROD); spe:cific deed language (1992 Consent Decree, updated by a future EPA letter) sediment/soil CALs: CR = 10-°; HI := 1.0;° and lead =500 mg/kg (ROD Am)

All portions of the Calumet aquifer aff'~cted by Midco I that exceed the GWCALs (ROD Am)

GWCALs: MCLs; CR = 10-5 ; HI = '1.0; and

AWaC X 3.9 (ROD Am)

Class I, non-hazardous injections well requirements identified in 40 CFR 144 Subparts A, B, 0, and E, and 146 Subparts A,S and F

(Statement of Work [SOW], ROD Am)

Maximum Allowable Concentrations (MACs): 6.3 times the Health Based Levels (HBLs,) used for Resource Conservation and Recovery Act (RCRA) delisting demonstrations in July 1991 (ROD Am as updated by ESD#1 and ESD#2)c

Effectiveness in enabling Construction requirements: continuous from lowering the water table ground surface to about 5 feet into clay confining

layer; hydraulic conductivity::;; 10-7 ern/sec (ESD#3)

Extend SVE treatment to Approximately 12 feet (ESD#3), 15 fflet highly contaminated soils (Operation, Maintenance, Monitoring, and Closure near and below the water Plan, OMMCP) table

Volume of soil where SVE Soils from surface to lowered water table within the must be performed groundwater barrier wall, which is about 54,000

b The CR (lifetime incremental cancer risk) and HI (hazard index) are calculated using exposure assumptions al1d toxicity factors defined in the ROD Am, including assuming a hypothetical lifetime residential exposure to soils having the sampling point concentrations.

C By not exceeding the MACs the groundwater meets the equivalent of RCRA delisting requirements and is considered non-hazardous pursuant to RCRA.


Component Applicability Performance Requirements (source)

Must be achieved in soil following completion of SVE

cubic yards of soil (ESD#3)

97% reduction in VOCs in treated soils (1992 ROD Am) based on before and after soil gas sampling (Final Desiqn Report, ENVIRON, April 2005)

Excavation or SIS Source area soils having the highest metals and cyanide contamination

A number of defined grid areas totaling 3,560 cubic yards unless post treatment sampling results demonstrates that it no longer is considered a principal threat (ESD#3)

On-site storage Sampling and treatment RCRA, 40 CFR 260 - 268 and off-site residuals, excavated soils EPA's Off-site Rule, 40 CFR 300.440 treatment/disposal that may contain

hazardous wastes

SIS Where SIS is performed instead of excavation, must be achieved in material treated by SIS

Metals~90-99% reduction in mobility except 500 micrograms per liter (ug/l) for coppe~; cyanide 40 ug/l; hydraulic conductivity s 10-7 cm/sec; unconfined compressive strength ~ 50psi; wet-dry durability s; 10% weight loss; freeze-thaw durability S;10% weight loss (ROD Am as modified in ESD#3)

Air emissions The CR and HI limitations apply to potential human exposures for each remedy component separately; the pound per hour and fugitive dust limitations apply to all remedy components operating at the same time

CR =1 X 10-7 ; HI =1.0;e

3 poundslhr of VOCs (Clean Air Act definition); Indiana Administrative Code 6-4 for fugitive dust

(ROD Am)

Final cover Areal extent

Construction requirements

Cover entire source area (ROD Am)

A multilayer cover; RCRA Subtitle C landfill closure requirements (ROD Am)

Remedy Implementation

Quality Assurance: In accordance with Consent Decree requirements, all sampling data for the remedial design and remedial action work have been generated in accordance with procedures in an EPA-approved Quality Assurance Project Plan (QAPP). The Second Five-Year Review Report explains how the number of groundwater monitoring parameters was reduced to the present list of 180 parameters. This list and the project

d The reduction in mobility is measured by comparing before and after treatment results of the Synthetic Precipitation Leaching procedure (SW-846, Method 1312).

e The toxicity factors and some exposure assumptions for calculation of CR and HI are defined in the ROD Am.


specific quan1i1ation limits are presented on the attached Table 1-1 from the 2005 Ground Water Monitoring Report. This same list of parameters is monitored in the treated groundwater prior to the deep well injection with the following exceptions: fluoride is added; and sulfide and hexavalent chromium are omitted. Fluoride concentrations have never exceeded the MCl (4 mgtl) in the influent and have ranged from 0.36 - 2.06 mg/l since March 2004. The influent data do not suggest that fluoride is likely to be a significant groundwater contaminant at Midco I.

The applicable EPA approved QAPP is the Remedial Design / Remedial Action Quality Assurance Project Plan dated May 14, 1993, as updated. In addition to the updates listed in the Second Five-Year Review Report, the QAPP includes the following updates:

• Revised soil gas sampling and analysis procedures in Appendix H of the Final Design Build Report (Revision 3) Soil Vapor Extraction / Air Sparging Midco " Superfund Site, ENVIRON, April 2005; and letters from ENVIRON dated October 7,2005 and November 14,2007; and

• Updated low flow groundwater sampling standard operating procedure in accordance with procedures e-mailed to EPA on June 13, 2005.

The QAPP as updated provides for 100% data validation for ambient air, air emission, and baseline and confirmation soil gas sampling, and for 10% validation of the groundwater data, with follow up validation of the rest of the data set if significant problems are identified in the 10% sample. The MRC has used an independent contractor to perform the data validations. The RPM routinely reviews the validation reports. Both the Weston and EPA staff were impressed with the high quality of the data validations received from the MRC's data validation contractor. As a n~sult,

although the Weston oversight contract included provisions for Weston to audit the data validation reports by checking the validation report against the raw data packages, EPA decided that this was not necessary.

EPA, IDEM, and Weston have routinely monitored data usage through reviE~w of ENVIRON's monthly progress reports, annual groundwater monitoring reports, capture zone evaluations, the baseline soil gas sampling report, quarterly and annual reports on the SVE, and interim soil gas sampling reports. The UIC has reviewed the deep well injection reapplication packages, and reports on deep well testing.

Weston, IDEM and EPA staff have overseen the annual groundwater sampling, some influent and effluent sampling, and some SVE, and soil gas monitoring events (see list of inspections in Table 4, at the end of this report). UIC oversees testing of the deep injection well. Soil gas sampling procedures were defined in a letter from ENVIRON dated October 7,2005. During field inspections EPA identified that ENVIRON was collecting soil gas samples after the sampling pump instead of before the pump as provided for in the approved plan. In response to this, ENVIRON revised the soil gas sampling procedure in a letter dated November 14, 2007.


During the last five-years, the MRC has constructed the SVE system at Midco I. EPA has overseen the quality of construction by reviewing and approving design documents, and by field oversight of the construction. Weston provided support to EPA in review of design documents, and IDEM also participated in this review. The design documents included: Construction Quality Assurance Plan, ENVIRON, May 2005 (attached to Technical Memorandum No.1), which defined procedures to be implemented to assure that the construction meets the specifications. The construction was mostly overseen by Weston. The RPM, IDEM site project manager, IDEM technical specialists, and Weston also reviewed the Construction Completion Report.

EPA, with support from Weston and IDEM, has overseen O&M of the pump-and-treat / deep well injection system and the SVE system through periodic on-site inspections (see Table 4) and review of related documents including: the OMMCP; revisions to the health and safety plans; monthly progress reports, and quarterly and annual SVE reports.

Health and Safety: Contractors for the MRC have prepared health and safety plans, which have been reviewed by EPA and Weston. The following Health and Safety Plans cover remedial design and remedial action activities:

• Remedial Design/Remedial Action Health and Safety Plan, Environmental Resources Management (ERM), May 14, 1993;

• Construction Health and Safety Plan, ERM August 1994; • Operating and Maintenance Health and Safety Plan, ERM, November 1996; • Task Specific Health and Safety Plan Addendum, SVE System Construction and

Operation; ENVIRON; May 2005 (attached to Technical Memorandum No.1, May 5, 2005);

• Letter re: Modification of Exclusion Zones, ENVIRON, October 14,2005.

Health and safety procedures were supplemented in an e-mail from ENVIRON dated July 22, 2005 to provide for a temporary support zone to provide relief to workers in the heat of the summer, and by confined space entry procedures for repair of the thermal oxidizer pilot ignition system.

Air monitoring using photoionization detector (PID) and hydrogen cyanide detectors was performed continuously near excavations, borings, and in the breathing zone during the following periods: at some locations during trenching for the groundwater barrier wall; and during advancement of augers for installation of the SVE and monitoring wells. Operations had to be shut-down a few times during installation of the SVE wells until PID levels dissipated.

IDEM, EPA and Weston inspections have included review of health and safety procedures (see Table 4). During an inspection of the installation of the temporary vapor barrier installation in May 2004, Weston noted the following health and safety concerns: the Health and Safety Plan was not present on-site; required personal


protective equipment was not being worn when Weston arrived; and significant dust was being generated by truck traffic. ENVIRON quickly addressed these concerns.

Air Emissions: During design of the SVE system, ENVIRON predicted air emission rates and performed ambient air modeling. Based on this, ENVIRON determined that a thermal oxidizer was needed to comply with air emission criteria. During startup testing of each header, Summa canister samples were collected from the inlet and outlet of the thermal oxidizer. Using these results, ENVIRON confirmed that the air emissions would comply with the criteria after treatment by the thermal oxidizer. During O&M, Summa canisters samples were collected from the inlet and outlet from the thermal oxidizer once per week during the four week commissioning period, and have been collected monthly thereafter. Sets of ambient air samples (one upwind and three downwind) were collected once during startup, twice during the four week commissioning period, and once per month during the first two months of operation.

ENVIRON has produced quarterly reports on the SVE O&M and monitoring. Each of these reports included any ambient air data collected, air emission data and an assessment of compliance with the air emission criteria. Because the ambient air samples did not identify any significant risk from the emissions, EPA approv1ed discontinuation of the ambient air sampling in a July 10, 2006 letter after the first two months of operation. Each quarterly report has demonstrated that the SVE system was in compliance with the air emission criteria. On August 6, 2008, EPA approved shutdown of the thermal oxidizer because VOC emissions were consistently below the air emission criteria in samples from the inlet to the thermal oxidizer, subject to restart if PID readings exceed 50 ppm. However, ENVIRON restarted the thermal mc:idizer on September 10,2008 because the emissions exceeded the 50 ppm PID criterion. On November 5,2008, EPA approved raising the PID threshold requiring restart of the thermal oxidizer to 175 ppm, based upon laboratory data collected and submitted by ENVIRON. The oxidizer remains off, subject to ongoing monitoring of the SVE effluent air stream.

Following inspection of SVE system on March 30, 2006, Weston expressed concern about detection of hydrogen cyanide in soil gas in SVE wells and advised that further monitoring should be performed. In an April 7, 2006 letter, ENVIRON responded that no further monitoring for hydrogen cyanide is necessary for the following reasons: hydrogen cyanide has been monitored in the breathing zone for health and safety reasons usin~J portable meters and has not been detected; and hydrogen cyanide is highly combustible and any hydrogen cyanide from the soil gas will be destroyed in the thermal oxidizer prior to emission. Therefore, EPA did not require addition of air emission monitoring for hydrogen cyanide.

On-site Storage and Off-site Disposal: In the 1989 ROD, EPA determined that the following listed hazardous waste as defined in RCRA regulations had been disposed on-site: F001; F002; F003; F005; F007; F008; and F009. For this reason, any residuals from treatment of groundwater (including spent pre-treatment filters) or soil, must be


handled and disposed of as a RCRA hazardous waste unless testing is conducted to demonstrate that the waste is not hazardous under RCRA. In 1999 EPA determined that spent pre-treatment filters could not be disposed under the site cover (January 14, 1999 conversation record), and that spent post-treatment filters qualify as debris and are regulated by 40 CFR 268.45 (December 21, 1998 memorandum).

On-site storage was inspected periodically by IDEM, EPA and Weston staff. Contaminated soil from drill cuttings from installation of wells in areas where off-site disposal of soil is required were placed in drums for on-site storage. Spent filters from the wastewater treatment were wrapped in plastic bags and stored under a tarp in 20 cubic yard roll-off boxes.

In response to a request from EPA, in March 2006, ENVIRON started including copies of hazardous waste manifests in the monthly progress reports, which are required under the Consent Decree. For the period from May 2004 through March 2006, ENVIRON provided a copy of the hazardous waste manifests with a letter dated April 7, 2006. Based on data from these manifests, the following off-site disposal occurred between May 2004 and December 2008:

• In June 2004, 2,100 pounds of waste activated carbon from treatment of the air stripper off-gas, was transported off-site for treatment/disposal at EO Resource Recovery, Inc. in Romulus, Michigan.

• In December 2005, 1,200 pounds of contaminated soil (drill cuttings from installation of the SVE and soil gas monitoring wells in grid areas where off-site disposal is required pursuant to ESD#3) were transported to the Michigan Disposal Waste Treatment Plant for treatment I disposal.

• In December 2005, 500 pounds of waste activated carbon used for control of air emissions during the SVE pilot testing, were transported off-site to Envirotrol in Darlington, Pennsylvania for reactivation.

• 1,100 cubic yards of spent filters were transported off-site for disposal at the Michigan Disposal Waste Treatment Plant, averaging about one 20 cubic yard roll-off box of spent filters per month;

To assure compliance with EPA's Off-site Rule, in February 2006, EPA confirmed that the Michigan Disposal Waste Treatment Plant and EO Resource Recovery were in compliance with federal and state environmental regulations. In an April 7,2006 letter, ENVIRON committed to regularly contacting EPA to assure that the disposal facilities being used are in compliance with environmental regulations.

Some wastes are being treated or contained on-site. Drill cuttings outside of the grids requiring excavation and off-site disposal were placed under the temporary vapor barrier on the south side of Midco I. Waste water from sampling operations and condensate from the SVE piping, is collected into a tank or barrel and gradually fed into the groundwater treatment system where it is filtered, treated by the ultraviolet/hydrogen peroxide (UV/HP) unit and then injected into the deep well.


Excavation of Sediment Areas to achieve Soil/Sediment CALs: The Second Five-Year Review Reporl includes a summary of the partial excavation of contaminated sediment areas performed in 1993. The unexcavated soil/sediment did not achieve the soil/sediment CALs. Furthermore, a screening of ecological risks indicates that contaminants in the unexcavated soil/sediment could cause a severe effect on invertebrates. As an interim measure, EPA approved leaving the contaminated soil/sediment in place enclosed within a fence until design of the final site cover (see attached Figure 1, Well and Piezometer Locations). ESD#3 eliminated the requirement that the contaminated sediments be treated by SIS. In 2005 as part of the SVE construction, the sediments that had been consolidated on Midco I and stomd under a plastic liner were spread and covered by the temporary vapor barrier and tht3 overlying clean soil. These excavated sediments are now included in the SVE treatment area, and will be contained under the final cover.

During design of the final site cover, EPA will require consideration of human health and ecological risks from the unexcavated soil/sediments. Options to address these soil/sediments include: covering the contaminated soil/sediment areas with dean soils; conducting further excavation and containing the excavated soil/sediments under the site cover; and leaving contaminated soil/sediments in place.

Deep Well Injection System: During the last five years, ENVIRON has complied with all technical requirements for O&M of the deep well, including monitoring and rlsporting requirements. The deep injection well is screened in the lower Mount Simon aquifer, which is not a drinking water aquifer at Midco I because the total dissolved solids exceed 10,000 mg/1. Deep well monitoring and testing requirements include: continuous monitoring and recording of injection pressure, flow rate, and annulus pressure to assure that an annulus pressure of at least 100 psi more than the injection pressure is maintained; daily recording of a fluid level corresponding to the annulus fluid pressure; monthly analysis of the fluid being injected; annual internal mechcmical integrity tests~ and five-year external mechanical integrity tests. Both the annual and five-year mechanic integrity tests were repeated during September 29 - 30,2008 and are now under review by UIC.

A comprehensive description of the existing deep well and EPA's requirements relative to its design, location, and O&M are in the underground injection well permit applications/reapplications. Review of these application/reapplications is primarily the responsibility of the UIC. EPA approved the most recent reapplication (Permit ReApplication Class I Non-Hazardous Injection Well, Midco I and /I Superfund Sites, Subsurface Technology, Inc., September 2005) on June 28, 2006. The next reapplication is due on or before December 28, 2013.

ENVIRON has implemented actions to improve operation of the deep well. In general during the last five years, the automatic acid injection has eliminated the nel3d for periodic shut-downs for well rehabilitation to control biological growth. In May 2004, the


deep well was shut-down for about 17 hours because of a PVC pipe crack. In response to this, ENVIRON replaced the PVC pipe with steel pipe. Because of relatively high injection pressures, on December 5 and 12,2007, flow from Midco II was turned-off to allow the low pH flow from Midco I to clean the deep well, and bleach was also added. On April 28, 2008, an EPA inspector observed that the steel piping in the deep well building was highly corroded. In an August 26, 2008 inspection, it was observed that the steel pipe had been replaced. According to ENVIRON, the steel pipe had been replaced with high pressure polyethylene piping.

O&M of the Groundwater Pump-and-Treat System: The project plan for O&M of the groundwater pump-and-treat system is: Ground Water Remediation Systems Operation and Maintenance Plan, ERM, August 1994, November 1996, as updated by a number of documents listed in the Second Five-Year Review Report. Continuous operation of the Midco I pump-and-treat system was initiated in February 1997. During the last five years, the system components have included: seven groundwater extraction wells; an equalization tank; prefiltration using cartridge filters; acid feed to prevent dirt, oil or precipitates from inhibiting UV light penetration; a UV/HP unit; a caustic feed system to neutralize the acid if necessary; automated post treatment monitoring for methylene chloride and vinyl chloride using a field gas chromatograph (GC); post treatment filtration using cartridge filters prior to combining the treated groundwater with treated groundwater pumped from Midco II; and pumping the combined flow through an underground pipeline to the deep well.

ENVIRON provides data and a summary of the groundwater pump-and-treat L&M and monitoring to EPA in monthly progress reports. During the last five years, O&M of the pump-and-treat system has been acceptable. The treatment system requires frequent maintenance. In a typical month there are ten or more shut-downs to address maintenance items. There were periodic shut-downs to replace the pre-treatment and post-treatment filters, and to correct the following categories of maintenance problems: UV/HP equipment and electrical problems; UV/HP lamp failure; pump problems; air compressor problems; deep well equipment problems; filtration equipment problems; computer problems; power failures; from 2004 through 2006 GC high methylene chloride shut-downs; and during 2005, shut-downs from Midco II when ENVIRON relied on dilution from Midco II to comply with the MAC for methylene chloride.

Groundwater Treatment and Monitoring to Meet the MACs, and Influent Trends: The Investigation and Monitoring Plan, (ERM, 1993) provides for the following monitoring for compliance with MACs:

• Every three months, sampling the treatment system influent for the comprehensive list of 180 groundwater monitoring parameters plus fluoride;

• Sampling the effluent annually for the comprehensive list of groundwater monitoring parameters;

• Monthly sampling of the effluent for surrogate contaminants; and • Hourly sampling for an indicator parameter.


The monthly surrogate contaminants have been VOCs and polyaromatic hydrocarbons (PAHs), which are analyzed at an off-site laboratory. The indicator paramet'9rs are methylene chloride and vinyl chloride from a field GC, which collects sample,s every hour. The pump-and-treat system automatically shuts-down if the GC detects vinyl chloride or methylene chloride exceeding its respective MAC. Use of the GC has made it easier to make minor adjustments to the system because grab samples of the effluent for off-site analysis of VOCs were not required. However, during hot weathHr peak shifting has caused unnecessary shut-downs.

During the last five-years, the only major trouble in achieving the MACs was during the initial dewatering, from May 2004 through January 2005, when there were multiple shutdowns in response to methylene chloride GC detections. These detections were confirmed by laboratory analyses of quarterly influent and monthly effluent samples in 2004, and once in January 2005. The highest detection was 67 ug/I (compared to the 31.5 ug/I MAC) in September 2004. Because the UV/HP does not appear to be capable of effectively treating methylene chloride, ENVIRON initially responded to this problem by reducing pumping rates within the barrier wall, but, unfortunately, this was prolonging the dewatering. Beginning in August 2004, ENVIRON changed the GC monitoring point to the combined Midco I and Midco II effluent instead of the Midco I effluent. and added monthly monitoring for VOCs and PAHs in the combined effluent. Subsequently, even when the Midco I effluent exceeded the MACs, the combined Midco I and tvlidco II flow that went to the deep well complied with the MACs. As a result, pumping within the barrier wall was increased and adequate dewatering was achieved.

The only other time when a MAC was exceeded in the effluent occurred in November 2008 when trichloroethylene was detected at 33 ug/I compared to the 31.5 ug/l MAC. However, trichloroethylene was detected at only 12 ug/I in the combined effluent. ENVIRON reported that they increased the hydrogen peroxide dose to attempt to improve treatment of trichloroethylene at Midco I.

Although the MACs only apply to the effluent, review of the influent data indicates which contaminants require treatment and can identify decreases in contamination, and comparison of the influent to the effluent data can indicate whether the contaminants are being treated. After March 2005, the VOC concentrations in the Midco I influent decreased sLibstantially from between 236 and 1,328 ug/l (total of detected VOCs) to between 1.8 to 140 ug/J. Apparently, these reduced concentrations were a result of maintaining groundwater levels within the barrier wall below the highly contaminated soils, and reduction in leaching after the temporary vapor barrier was installed. Since January 2005, the only influent detection exceeding a MAC was trichloroethylene in March 2006 (37 ug/l compared to the 31.5 ug/I MAC). During the last five years, the only contaminants that have exceeded MCLs (which are more stringent than the MACs and are not required to be achieved prior to deep well injection) in the influent are benzene, trichloroethene, and vinyl chloride. The quarterly influentleffluEmt samples indicate that the treatment system generally reduces benzene,


trichloroethene, and vinyl chloride concentrations to below the MCLs in the effluent. In addition, cis-1 ,2-dichloroethylene; trans-1 ,2-dichloroethylene; ethyl benzene; toluene; xylene; iron; and cyanide are reduced to very low concentrations in the effluent. The treatment system has little impact on chloroethane; 1,1-dichloroethane; methylene chloride; or 1,1,1-trichloroethane concentrationsf

.

Groundwater Capture Zone Evaluation: The target groundwater capture zone is shown in the attached Figure 4 from the Second Five-Year Review Report. The Second FiveYear Review Report also includes an explanation of: how the target groundwater capture zone was determined; how EPA determined that higher pumping rates were required to achieve the target capture zone; how EPA and ENVIRON agreed to add extraction well, EW-7; and how it was determined that pumping a total of 32 gpm in the following distribution achieved the target capture zone: EW1 =7.5; EW2 =7.5; EW3 = 2.9; EW4 =2.7; EW5 =3.4; EW6 =0.5; EW7 =7.5. The pump-and-treat system operated using this pumping distribution from January 2002 until December 2003, when the Midco I source area, including EW3 and EW4, was enclosed within a groundwater barrier wall. Subsequently, EW3 and EW5 have been pumped for dewatering purposes - not for groundwater capture. In a May 26, 2004 letter, ENVIRON provided modeling demonstrating that groundwater capture could be maintained at lower pumping rates because of the presence of the barrier wall. In a January 13, 2005 letter, EPA approved reducing pumping rates outside of the barrier wall to a total of 21 gpm in the following distribution: EW1 =6.1; EW2 =6.1; EW4 =1; EW6 =1.7; and EW7 =6.1.

For the fifty-six months from May 2004 until December 2008, ENVIRON achieved average pumping rates that were 95% or more of the target rates except during thirteen months, when there were prolonged down-times due to power outages, repairs, testing, or maintenance.9 On June 24,2005, ENVIRON collected water level measurements when pumping rates were about equal to the target rates. Using these water level measurements, ENVIRON ran a model (which replicated a model prepared by Weston

f It should emphasized that there is no MAC for chloroethane, and 1,1-dichloroethane; and 1,1,1trichloroethane concentrations in both the influent and effluent from December 2003 to September 2008 have been well below their respective MACs (880 ug/I for 1,1-dichloroethane, and 1,260 ug/I for 1,1,1trichloroethane), which indicates that treatment is not required. Concentrations of methylene chloride in the influent and effluent samples only exceeded the MAC in the 2004 samples as discussed above. g Months when the average pumping rate was less than 95% of the target rate included: November 2008 (82%) primarily because of deep well flow meter and freeZing problems; September 2008 primarily because of the annual deep well mechanical integrity test; June 2008 (62.2%) primarily because of shutdown from power outage, and for replacement of damaged electrical components; December 2007 (94.5%) primarily because of shut-down from power outage; October 2007 (92.6%) primarily because of shut-down for the annual deep well mechanical integrity test; August 2007 (84.9%) because of power outage and maintenance shut-downs; January 2007 (94.5%) because of a power outage and maintenance work; October 2006 because of power outages and annual deep well mechanical integrity and pipeline pressure tests; November (86.4%), October (71.1 %) and September 2005 (91.8%) primarily because of reduced flow because of operation of backup pump during replacement of deep well pump; November 2004 primarily because of breach in Midco II pipeline; and October 2004 primarily because of power failure and Midco II clarifier maintenance.


in 2001), which showed that the target capture zone was achieved (see attached Figure 1-5, Capture Zone Analysis). ENVIRON performed another water level SUrvl3Y on May 1,2008 when pumping rates substantially exceed approved rates, but ENVIRON's surfer plots of the May 1, 2008 data are not definitive. Considering that in general the target pumping rates are being achieved, and GWCALs are not exceeded in downgradient boundary monitoring wellsh

, it appears that adequate groundwater capture is being maintained.

Groundwater Cleanup: ENVIRON has reported that through Decemberr 2008, about 145 million gallons of groundwater has been pumped and treated at Midco I. Through March 2008, ENVIRON estimates that the pump-and-treat system has removed 572 pounds of VOCs, and that 100 pounds were removed between September ~W04 and March 2008. From 12/5/06 - 3/12/07, it is estimated that 3 pounds were removed, which averages 0.03 pounds/day.

ENVIRON collected a round of groundwater samples from pumping, and monitoring wells, and piezometers located outside of the barrier wall in May and June 2004, June 2005, and June 2008 (see attached Figure 1 for well and piezometer locations). Five pumping wells were sampled during each event, plus 28 monitoring wells/piezometers in 2004; 29 in 2005; and 27 in 2008 (monitoring wells N-10 and N-30 could not be sampled because the concrete debris piles caused safety concerns). All of the samples were analyzed for VOCs, metals, cyanide, and sulfide. Selected samples were analyzed for hexavalent chromium. The 2005, samples were analyzed for the full 180 parameter list (plus sulfide), including direct injection VOCs, semivolatile ornanic compounds, polycyclic aromatic hydrocarbons, PCBs, organochlorine pesticides, organophosphorus pesticides, and herbicides.

In general, comparing the 2004, 2005 and 2008 sampling results, shows a significant reduction in contaminant concentrations and detections exceeding the GWCALs, but contaminant concentrations still exceed GWCALs at many locations. The attached Table 4-2 from the 2005 Annua/ Ground Water Monitoring Report and TablH 4-2 from the 2008 Annual Ground Water Monitoring Report tabulate the contaminants that exceeded or contributed to exceeding a GWCAL.

The following table compares all of the VOC detections exceeding the GWCALs in monitoring and pumping wells outside of the barrier wall in 2004, 2005 and 2008. The table shows that although there has been a reduction in VOCs, GWCALs were still exceeded for benzene (GWCAL = 2.69 ug/I) and vinyl chloride (GWCAL = 1: .32 ug/I) in the vicinity of EW4.

h In 2008, GWCALs were achieved at P-4 (except for iron), K-10, K-30 and P-1, and in 2005 at N-10 (except for bis(~~-ethylhexylphthalate and silver), and N-30.


Table 5: Comparison of VOCs (ug/l) Exceeding GWCALs Outside Barrier Wall in 2004, 2005 and 2008 (Detections exceeding GWCALs are bolded)

WELL I VOC (GWCAL) 2004 2005 2008 P10 / benzene (2.69) 8 3.7 ::50.5 EW4/ benzene (2.69) 31 16 6.8 EW4/ vinyl chloride (1.32) 11 7.7 2.6

Monitoring wells have not been sampled within the barrier wall during the last five years, but pumping wells, EW3 and EW5, provide some data on groundwater within the barrier wall. Trends of some VOCs in EW3 and EW5 are presented in the following table. Groundwater at EW5 still exceeded various GWCALs in 2008.

Table 6: Comparison of Benzene, Cis-1,2-Dichloroethylene, 1,2-Dichloroethane, Methylene chloride, Trichloroethylene, and Vinyl Chloride Concentrations (ug/I) in EW3 and EW4 in 2004, 2005, and 2008 (Detections exceeding GWCALs are bolded)

WELL I VOC (GWCAL) 2004 2005 2008 EW3/ benzene (2.69)

cis-1 ,2-dichloroethene (70) 1,2-dichloroethane (1) methylene chloride (5) trichloroethene (5) vinyl chloride (1.32)

67 720 1.8 150 21 100

23 16

::53.1 ::50.93

2.3 6.7

1.8 2.6

::50.5 ::50.5 1.8 1.8

EW5/ benzene (2.69) cis-1,2-dichloroethene (70) 1,2-dichloroethane (1) methylene chloride (5) trichloroethene (5) vinyl chloride (1.32)

16 87

::50.5 ::50.72

19 39

4.8 25

0.25 10 8.1 33

0.56 150 4.3 11

470 25

The following table compares the frequency of detections and maximum detections for inorganic contaminants that exceeded the GWCALs in 2005 and 2008. Except for the sulfide, there was a reduction in the frequency and maximum detections. Detections of arsenic, cyanide, sulfide, iron and thallium in potentially upgradient wells (010, 050, MW11 S, and MW4S) indicates that these contaminants have an off-site component. The silver contamination previously detected does not appear to result from Midco I.


Table 7: Comparison 2004 and 2008 of Frequency of Detections and Maximum Detections of Inorganic Contaminants Exceeding GWCALS

CONTAMINANT (GWCAL in ugll)

2005 DETECTIONS ~

GWCAL 2 2 10

1

2008 DETECTIONS ~

GWCAL

2005 MAXIMUM (ugJI) / WELL

2008 MAXIMUM (ugJI) J WELL

arsenic (6) 1 26.3/ MW4S 12.71 G10 barium (1,000) 1 1,9001 H30 1,310/1-130 cyanide (20.3) 8 90.71 MW4S 77.11 EW6 sulfide (12.6) 21 2,6001 H30 13,600/MW11 S iron (3,900) 1 231 16 29,000/EW7 21,700/H}0 nickel (350) 1 Thallium (3) 3

0 0

4291 H30 7.31 H10

1541 H30 All NO

l§f1ver (1) 1 o 1.4/N10 All NO

The following table summarizes detections of semivolatile organic compounds, pesticides, and PAHs that exceeded a GWCAl in 2005. There were no detections of direct injection VOCs, organophosphorous pesticides in 2005, and the only detections of a herbicide were two detections of 2,4-0 at 2.5 and 5 ug/I, which are far below the MCl of 70 ug/f. Note that elevated pentachlorophenol was also detected at MW-4S in 1996, elevated PAHs at MW11 in 1996 and 1997, and elevated dieldrin at a number of wells in 1997. The pentachlorophenol, bis(2-ethylhexyl)phthalate, and chrysene detections do not appear to be focused in groundwater downgradient from Midco I. Detection of dieldrin in potentially upgradient wells indicates that this contamination has an off-site component.

Table 8: Summary of Semivolatile Organic Compound, Pesticide, and PAH Detections Exceeding a GWCAL in 2005 (cone. in ug/l)

CONTAMINANT (GWCAL) NUMBER ~ GWCAL MAXIMUM DIETECTION I WELL

pentachlorophenol (1 ) 1 19/ MVV4S dieldrin (0.00741) 10 0.023/ H30 bis(2-ethylhexyl)phthalate (6) 8 26/ P1, P4 chrysene (2.81) 1 28/ MVV11S

Once the SVE treatment is completed within the barrier wall, the MRC is considering breaching the wall to allow groundwater to flow through the area within the barrier wall. There is concern that the groundwater may be re-contaminated by VOCs and possibly by other contaminants if soil concentrations needed to be protective of groundwater are not achieved by the SVE treatment, To address this concern, the MRC is evaluating options to treat the water, as may be necessary, prior to allowing it to flow outside the barrier wall.

Soil Treatment: Conceptual design information on the barrier wall and SVE system was included in Soil Treatment Design/Build Alternative Remedy Revision 1 Midco I and


Midco /I Superfund Sites, ENVIRON, July 2003. More detailed design documents were submitted later as additional design data were generated. The final layout of the barrier wall and SVE system is shown on the attached reduced Figure 2 from the Construction Completion Report for the Soil Vapor Extraction System, ENVIRON, November 2006.

The groundwater barrier wall was constructed during November and December 2003. The barrier wall was constructed by in-situ mixing of bentonite with the native soil using a trenching machine to produce a 4% bentonite mix. The depth of the barrier wall ranges from 25 to 29 feet, which extended at least two feet into the underlying confining layer. Based on data collected during construction, the barrier wall achieved all construction requirements.

Dewatering within the barrier wall began in December 2003, by pumping wells EW3 and EW5. The purpose of the dewatering is to lower the water level, thereby allowing the SVE to treat the contaminated soils above the (now decreased) water table within the barrier wall. ESD#3 provided the target of lowering the water table 12 feet, but this was increased to 15 feet in the approved OMMCP. Based on modeling, ENVIRON predicted that achieving this target would take less than twelve months, but it actually took 17 months. In addition, more sustained pumping has been required than expected to keep the water table low. During the dewatering, high methylene chloride detections in the Midco I effluent forced ENVIRON to reduce the dewatering rate. In addition, it is apparent that infiltration of precipitation slows the dewatering rate during certain seasons. This was probably especially true before completion of the temporary vapor barrier in June 2005 reduced infiltration. From June 2004 to April 2005, ENVIRON added pumping from some of the monitoring wells inside the barrier wall to increase the dewatering rate. The dewatering objective was achieved in May 2005, but, except during a few months in the summer of 2005 and 2006, ENVIRON has had to continue pumping within the barrier wall to maintain the reduced water table. ENVIRON has maintained the water table at acceptable levels (generally 12 - 15 foot of drawdown).

In March 2005, the site was graded for installation of the temporary vapor barrier, which was completed in June 2005. The temporary vapor barrier consists of a layer of nonwoven geotextile underlying a layer of 12 mil scrim reinforced polyethylene. The temporary vapor barrier was generally sloped to promote run-off, but some hummocks remained. Twelve inches of clean soil were placed over the polyethylene.

In July and August 2005, 33 vertical four-inch PVC SVE wells were installed approximately 60 to 75 feet apart. Thirty-two (32) one-inch PVC vapor monitoring wells were also installed. Special procedures were followed to prevent contact with contaminated soils, and to seal the temporary vapor barrier around these wells. The SVE wells utilized 4-inch PVE screens installed at 5 to 13 feet below ground surface. Two vapor monitoring points were installed at 16 locations, one screened from 11.5 to 13 feet below ground surface, and the other 3 to 4 feet below ground surface.


The baseline soil gas measurements, which will be used for calculation of the % reduction in VOGs, were performed in October 2005. The measured % reductions will be used to monitor for achievement of the 97% reduction performance stanclard for SVE. The total of VOG detections in the baseline samples were as high as 225,000,000 ug/m3

.

From November 2005 to February 2006, the thermal oxidizer, blowers, and piping were installed, and, in January and February 2006, were tested. The thermal oxidizer was equipped with a %LEL (lower explosive limit) meter on the inlet, which triggE~rs an automatic shut-down at 50% LEL. Special precautions were followed durin9 start-up to prevent creating an explosive mix of vapors at the blowers, which were not intrinsically safe for explosive gases. During the first four weeks of operation, dilution air was added either at the SVE well heads or at the inlet to the blower in order to limit LEL levels. The thermal oxidizer was also equipped with a display of the stack and chamber temperatures, and a chart to constantly record these temperatures. The the'rmal oxidizer was designed to operate with a chamber temperature of 1,600°F. Traps were added to the SVE header piping to collect condensate, and condensate was. collected in a tank before the blower.

During start-up testing of the SVE, each SVE header was started up separately, and measurements performed, including: %LEL at the thermal oxidizer; VOG concentrations before and after the thermal oxidizer; PID, air flow, and vacuum in SVE wells; and vacuum in vapor monitoring points. This data was used to assure that the SVE system would be effective, would operate safely, and would operate in compliance with air emission criteria.

After continuous operation was initiated in March 2006, a weekly, monthly, and quarterly sampling schedule started, and O&M and monitoring progress reports were submitted quarterly. The SVE system was designed so that one-half of the SVE wells would be subjected to a vacuum at any given time, while the other half would serve as air inlet wells. The O&M plan provided that the configuration of vacuum and inlet SVE wells would be switched periodically. In general, pressure and oxygen monitorin~l of the vapor monitoring points has indicated that the SVE was affecting the entire target treatment area. The thermal oxidizer operated continuously (until August 1:~, 2008 after shut-down was approved) with the chamber temperature of 1600oF. Each monthly Summa canister sample confirmed that the emissions complied with the air emission criteria, and, except in one month, that a greater than 95% destruction removal efficiency was achieved.

The primary potential O&M deficiency has been that flow rates from the SVE wells have been less than the design flow; and periodic shut-down of certain SVE wells. ENVIRON has reported that the excessive water in the pipelines is generally the caUSH for the reduced flow rates and shut-downs. ENVIRON suspects that the excessive water was from entrainment of groundwater. ENVIRON has attempted to address this problem by increasing pumping rates within the barrier wall in order to lower the water table.


ENVIRON has also tried changing the configuration of active SVE wells. To date ENVIRON has had limited success in increasing the SVE air flow rates to near design rates. ENVIRON has stated that they will test air injection if the operational changes do not result in significantly increased flow rates. ENVIRON also reported frozen ground conditions during the winter resulted in decreased flow rates from SVE wells.

The system has been very effective in removing VOCs. From March 2006 through November 2008, an estimated 45,000 pounds of VOCs were removed by the SVE system. The quantity of VOCs removed is not nearly as much as ENVIRON's estimate of total VOCs in Midco I soil (180,000 pounds of organic contaminants, including about 125,000 pounds of VOCs (ignoring the 2X safety factor for tentatively identified compounds), based on soil data from the RI data, see Table 3, Soil Treatment Design/Build Report Alternative Remedy). The highest removal rate was in 12.6 pounds/hr measured in April 2006 during the seventh week of operation. This was less than the average removal rate predicted by ENVIRON (16 pounds/hr). In general, the removal rate exceeded 1 pound/hr until January 2007. In 2007 removal rates ranged from 0.31 to 3.68 pounds/hr; and in 2008 from 0.55 to 1.07 pounds/hour.

The minimum performance standard for the SVE is achieving a 97% reduction of VOCs in soil. EPA has agreed to use soil gas data to evaluate achievement of this standard. In August - September 2008, ENVIRON collected eleven soil gas samples at nine locations to evaluate the progress of the SVE. The percentage reduction in total detected VOC between the baseline (collected in October 2005) and August and September 2008 samples ranged from 68% to 100%. The weighted average total percentage reduction ranged from 94.4 to 97.0% depending on whether the high or low of duplicate samples are used.

Although the SVE system has been successful in removing VOCs from the vadose zone and aquifer soils, and a percentage reduction approaching 97% has been achieved, VOCs will remain in the Midco I soils once operation of the SVE is terminated. Recent VOC removal rates indicate that a significant quantity of VOCs can still be removed from the Midco I soil.i Furthermore, based upon preliminary analysis of the soil vapor samples collected in August 2008, it is possible that groundwater could become reimpacted with VOCs at unacceptable concentrations once the water table within the wall is allowed to rise with the future cessation of pumping) EPA and the MRC are

i If it is assumed that the average rate of removal over the next two years will be about 0.3 pound/hour or 7 pounds per day (about one-third of the August - October 2008 rate), then another 5,000 pounds of VOCs, including 300 pounds of carcinogenic VOCs, would be removed. This removal rate substantially exceeds the removal rate of the pump-and-treat system. j To assess the potential for the VOC soil contamination to contaminate the groundwater, IDEM calculated the air concentrations that would be in equilibrium with methylene chloride, trichloroethylene, and tetrachloroethylene in water at their GWCALs (5 ug/I) using Henry's Law constant. The results were:

methylene chloride: 562 ug/m3;

trichloroethylene: 1,894; tetrachloroethylene: 3,122.


evaluating the potential impacts to groundwater quality if this occurs and potential remedial options to prevent unwanted impacts.

Excavation of Soils with High Cyanide and Metals Concentrations and Final Site Cover Design and performance of excavation of soils with high cyanide and metals concentrations and the final site cover is being delayed until completion of tile SVE. The design of the final site cover will also address the areas where sediment excavation did not achieve the soil/sediment CALs.

Vapor Intrusion: At this time, there is no concern about vapor intrusion because: only trace concentrations of VOCs are present outside of the groundwater barrier wall; and within the groundwater barrier wall any VOC vapors are being contained by the SVE system and the barrier wall.

In the past, the distance from Midco I to residences provided sufficient protection from vapor intrusion. The closest residence was about 500 feet south of Midco I (this building now appears to be used for truck repairs). The nearest residential area is in Hammond, located approximately 1,500 feet west of Midco I. As can be sel3n from Figure 1, there are a number of buildings within 150 feet of Midco I. It appears to be possible that vapor intrusion impacted these buildings in the past, but it is ul1likely that it caused a significant health impact because all of the buildings are constructed on a slab, and are used for industrial and business purposes. The surrounding buildings include offices of the Indiana Department of Transportation, a trucking facility, a body repair shop, and other businesses.

Institutional Controls (ICs) and Access Restrictions

Presently the Midco I property is being used only for cleanup activities. ThE~ 1989 ROD requires access restrictions by construction of a fence around the site and imposition of deed restrictions. The MRC is maintaining a fence around the contaminated soil and sediment areas, and the groundwater treatment facility. The present extent of the Midco I fence is shown in Figure 1.

Periodic inspections by EPA and IDEM staff have confirmed that the fence is being adequately maintained, except that huge concrete debris piles are encroaching on the east boundary fence and into the access areas for monitoring wells N10, N::m and peizometer P1. In 1998, the MRC was contacted by the operator of the concrete recycling business east of Midco I. The operator had acquired some property that is part of the Midco I site and talked of taking down some Midco I fences to extend his

All except two of the August - September 2008 soil samples, exceeded one or more of the equilibrium soil gas concentrations by large amounts. The highest detected soil gas concentrations and the number of times it exceeds the concentration in equilibrium with the MCLs were:

methylene chloride: 6,500,000 ug/m3 = 12,000 X 562 ug/m3;

trichloroethylene: 2,700,000 ug/m3 = 1,400 X 1,894 ug/m3;

tetrachloroethlylene: 97,000 ug/m3 = 31 X 3,122 ug/m3.


operation. At that time, the concrete debris piles were beginning to encroach upon the Midco I fence and monitoring well areas. The MRC sent a letter to the operator dated November 4, 1998 explaining that the MRC must have continued access to the property to conduct the remedial action. The debris piles have further encroached on the fence, and the attached pictures taken by ENVIRON on April 21,2008 show the present conditions in that area. In 2008, ENVIRON could not sample groundwater monitoring wells N1 0 or N30 because of the safety hazard presented by the huge concrete debris piles. No action has been taken to correct the concerns caused by the concrete debris piles because there is no public access through the east fence (the property east of Midco I is itself fenced and used only for industrial purposes), and because data from N10 or N30 is not critical to the progress of the site cleanup, at this time.

In addition to the fence, access is restricted by ENVIRON personnel, who are present on the site to operate the ground water treatment system almost every day. These personnel will be able to observe evidence of trespassing on the site and initiate corrective measures. Because of the on-site presence, during 2007 off-site pumping at Midco " that had potential to draw contaminated groundwater off-site was identified and the problem corrected. The MRC was not notified in advance of this off-site pumping.

The 1989 ROD and 1992 ROD Amendment include deed restrictions as a component of the remedy. Deed restrictions are one type of IC (a non-engineered instrument, such as administrative and/or legal control, that help to reduce the potential for exposure to contamination and protect the integrity of the remedy). In general, compliance with ICs is required to assure long-term protectiveness for any areas which do not allow for unlimited use or unrestricted exposure.

The Consent Decree requires that the Settling Defendants perform the following actions relative to deeds and land records applying to the property that they own:

• File an EPA-approved notice to subsequent property owners in the land records of Lake County, Indiana that they own part of a facility where hazardous substances were disposed;

• Notify EPA and the State of Indiana prior to transfer of the property, and assure that any deed, title or other instrument of conveyance of the property must contain a notice that the property is subject to the Consent Decree;

• Record a copy of the Consent Decree in the chain of title in the land records of Lake County, Indiana for property that they own; and

• File in the land records a deed/use restrictions in the form shown in Appendix 8 of the Consent Decree.

To the extent that property is not owned by the Settling Defendants, the Consent Decree requires them to use their best efforts to cause the owners of such property to implement the deed notices, and restrictions identified above.

In 1992 and 1993, the Settling Defendants filed deed restrictions in the land records for some, but not all, of the property within the Midco I site boundaries using the language


required in the Consent Decree. In an action outside of the Consent DecreE~, on September 27,2007, the City of Gary passed an ordinance prohibiting drilling of new wells to be used as a source of potable water, requiring existing private wells to be connected to the City water system if possible, and requiring non-potable water wells to be registered.

During 2008, EPA performed an initiallC evaluation. EPA determined that the existing access controls along with the City of Gary's groundwater ordinance provide sufficient protection from current public health threats. However, EPA identified the following concerns that may impact the long-term protectiveness of the remedy: deed restrictions required in the Consent Decree are not in place on all properties where contaminants exceed the soil CALs and/or the GWCALs; the existing deed language may not be effective; it is possible for non-potable water usage to draw contaminated groundwater off-site; and existing project plans do not include IC monitoring. Therefore, EPA has determined that the following additional steps must be taken: update deed language for all properties where unrestricted usage or access presents an unacceptable threat to human health or the environment; work with the City of Gary to assure notifilcation of non-potable water usage near Midco I; prepare and implement an IC monitoring plan; and further evaluate and implement ICs, as necessary to enhance the long-term protectiveness of the remedy. EPA is currently in communication with the MRC regarding this issue.

O&M Costs

The MRC has not provided EPA with annual O&M costs. During the last five-years, EPA has cooperated with the MRC in their efforts to eliminate unnecessary O&M costs by approving the following changes:

• Discontinuation of annual monitoring of groundwater within the barrier wall while the ba rrier wall is intact;

• Waiver of annual groundwater monitoring for 2006 and 2007; • Discontinuation of ambient air monitoring for SVE operation (see May 7, 2007

letter); • Shut-down of the HP/UV system (see May 7,2007 letter, but in fact, ENVIRON

has found it necessary to continue using the UV/HP unit); • Waiver of annual soil gas sampling for 2007; and • Shut-down of the thermal oxidizer for the SVE system (see August 2008 letter).

v. Progress Since the Last Review

Following is the protectiveness statement from the Second Five-Year Review Report:

In summary, the access / deed restrictions and groundwater remedial actions at Midco I currently protect human health and the environment because contaminatea' groundwater from Midco I is being contained, because air emission and del'~p well


injection requirements are satisfied, and because direct contact with the contaminated soils and groundwater is being prevented. However in order to assure that the remedy remains protective the following actions need to be implemented:

improved notification and reporting of operating and maintenance problems affecting compliance with the MAGs; more comprehensive data validation; closely observe trends in metals and cyanide concentrations in P-1 and outer monitoring wells; install a nest of monitoring wells at P-1 and better characterize off-site and background contamination, if necessary; when evaluating a request for shutdown update the groundwater cleanup action levels if necessary.; and during design of the final site cover, consider the human health and ecological risks from the remaining soil contamination, and further characterize these risks if necessary.

The sediment excavation, soil treatment and site cover phases of the remedy are expected to be protective of human health and the environmental upon completion, and the interim exposure pathways that could result in unacceptable risks are being controlled.

The following table summarizes the status of the issues identified in the Second FiveYear Review Report:

Table 9: Actions Taken Since the Last Five-Year Review Issues from

Previous Review

Recommendationl Follow-up Actions

Party Milestone Date

Action Taken and Outcome Date of Action

1. Data Validation

Follow up on problems identified in 10% of data manually validated

MRC 4/8/04 EPA sent letter to MRC requiring corrective action. MRC agreed to this change.

4/8/04

2. Reporting of changes affecting MAC compliance

Notify EPA of changes, and report operating parameters in monthly progress reports

MRC 5/6/04 EPA sent letter to MRC requiring corrective action. MRC sent letter agreeing to corrective action and started adding additional operating parameters to monthly progress reports.

5/6/04

5/26/04


Issues from Recommendationl Party Milestone Action Taken and Outcome Date of Previous Follow-up Actions Date Action Review

3. Off-site contamination

Closely observe trends in boundary wells / better characterize off-site contamination, if necessary

MRC Ongoing Data from the 2004, 2005 and 2008 annual groundwater monitoring have been closely reviewed. The silver, pentachlorophenol, bis(2ethylhexyl)phthalate, and chrysene contamination does not appear to be focused on Midco I. There appears to be an off-site component to the arsenic, cyanide, sulfide, iron, and thallium contamination. Also see discussion

Ongoing

below.

4. Soil Implement soil MRC Ongoing SVE soil treatment is being implemented Ongoing exceeds soil treatment and final CALs site cover

5. Extent of Closely observe MRC Ongoing Data from 2004, 2005, and 2008 annual Ongoing chromium, trends in P-1, and groundwater monitoring have been closely nickel, install a well nest at observed. No VOCs, chromium, nicknl or cyanide P-1, jf necessary cyanide were detected in the sample from plume P-1 in 2008.

6. Delay in Accelerate MRC 5/6/04 EPA sent letter to MRC requiring 5/6/04 soil treatment dewatering, and corrective action. The SVE treatment

implement SVE started in March 2006

7. GWCALs ·Jpdate GWCALs EPA Future No action to date Future

8. Soil CALs Jpdate soil CALs EPA Future No action to date Future

The Second Five-Year Review Report identified the following apparent contaminant trends to watch for off-site source of metal contamination:

Vanadium in G30 increased from 24 to 224 ug/l from 1993 - 2002; Iron in K10 increased from 3,680·to 13,400 ug/l from 1993 - 2002; Arsenic in MW4S increased from 3.5 to 15.8 ug/l from 1999 - 2002; Antimony in N10 increased from 1.6 to 20.7 ug/l from 2001 - 2002; Selenium in N10 increased from 2.5 to 16.7 ug/l from 1999 - 2002; Vanadium in N10 increased from 3.4 to 117 ug/l from 1993 - 2002; Cyanide in 010 increased from 10 to 73.6 ugll from 1998 - 2002.

Each of these apparently increasing trends was reversed in the 2004 throu1:;lh 2008 data, and, as a result, it appears that the apparent trends are only part of the random variability of the sample results. No new increasing trends in contaminants in site boundary wells were observed from the 2004 through 2008 data. The incmased frequency of detection of sulfide appears to be related to improved analytical techniques rather than increased concentrations.

The 1998 Five-Year Review Report noted that unexcavated soil I sediment did not achieve the soil CALs and contaminants in the unexcavated soil I sediments exceeded ecological risk screening concentrations. These unexcavated soil I sediments have been enclosed within the site fence. The site fence is preventing human contact. The ecological risk will be addressed during design of the final site cover. Because the soil


treatment has not been completed, no progress has been made in addressing the ecological risk from these soils. The Addendum to the Five-Year Review Report contains the following further explanation of the ecological risks from the soil sediment areas. This explanation is still valid.

Although the ecological screening identified that contaminants remaining after excavation are likely to cause severe impact on an aquatic micro-invertebrate community, the value of the ponded areas near Midco I [as] an aquatic habitat is very low. This is why one of the options mentioned in the December 1, 1997 memorandum from the biologist is filling in the ponds. In addition, carcinogenic polyaromatic hydrocarbons, polychlorinated biphenyls, bis(2-ethylhexyl)phthalate, and lead are commonly detected in urban environments, and the detections are low enough to suggest that they may be at or near background concentrations for that area. EPA took this information (small affected area, small value as a habitat, and low concentrations) into account in allowing the MRC to enclose the sediment area with a fence and divert ditch water around the contaminated sediment area as an interim measure. In addition, it will be less costly and more convenient for the MRC to further address the excavated areas in conjunction with construction of the final site cover than to conduct a special evaluation of the hazard and mobilize to take an action now.

VI. Five-Year Review Process

Administrative Components

IDEM staff were notified of the initiation of the third five-year review process on August 14, 2008. IDEM, the MRC, ENVIRON and LFR were notified in writing by an EPA letter dated September 8, 2008. On September 4, 2008, the RPM completed a first draft of the Third Five-Year Review Report and distributed it to: Regional Counsel, Region 5; Stephanie Andrews, IDEM Site Manager; William Bates, UIC; Donald Bruce Chief Region 5 Remedial Response Section #5; Stephanie Linebaugh, EPA Region 5 FiveYear Review Coordinator; and to Sheri Bianchin, IC Coordinator. After obtaining comments on the first draft, a second draft was distributed on December 1, 2008 to the previously listed parties plus: Barbara Coughlin, PhD., ENVIRON; William Bow, LFR Inc.; the City of Gary; and the Gary-Chicago Airport Authority.

Community Notification and Involvement

Janet Pope, EPA Community Involvement Coordinator, arranged to have a notification of the Five-Year Review published in the September 7,2008 edition of the Gary PostTribune (attached). EPA received no public comments or inquiries in response to this notification. When the third five-year review is completed, a notification and summary of results will be published in the same newspaper, and the Third Five-Year Review Report and other updates to the administrative record will be made available at the Gary Public Library, as well as at EPA Region 5's Records Center.


Since 2002, EPA staff have been in communication with the Federal Aviation Administration, the Gary-Chicago Airport Authority, and other agencies regarding an environmental impact statement for expansion of the airport. Virginia Lazewski of EPA coordinated with the RPM regarding information on and the impact on Midco I. The final environmental impact statement was issued in October 2004. EPA provided comments in a letter dated November 22,2004.

As part of EPA's Superfund Redevelopment Initiative, from 2002 to October 2006, E2

Inc., an EPA contractor, performed a reuse assessment for Superfund sites in Gary, Indiana, including Midco I. The purpose of the reuse assessment was to assist the City of Gary with reuse planning. The activities included evaluating site and market conditions, and considering reuse options. Typically, there is a more thorough assessment of reuse options, and involvement of the community, but after consideration of the timing, legal, administrative, and technical obstacles plus the low market demand for the Midco I property, the effort did not proceed to that phase. The final report was issued in October 2006. Please note that the figure of Midco I in that report has the following mistakes: the figure shows a pondlwater retention in the middle of Midco I, which was actually the area where contaminated sediments had been consolidated and covered with a plastic liner; and the figure shows a fence only around the source area when actually the fence has been expanded to include the groundwater treatment facility and the contaminated sediment areas.

In October 2004, EPA sent a copy of the Second Five-Year Review Report to the City of Gary, Department of Environment, and to the Chicago-Gary Airport.

On January 5,2005, EPA issued a notice in the Gary Post-Tribune regarding the changes in the remedy that EPA approved in ESD#3, including the addition of the groundwater barrier wall, SVE, reducing the amount of SIS, and relaxing SIS performance standards. EPA received no public comments on ESD#3. In ..June 2005, EPA issued a fact sheet describing the final design of the Midco J SVE system. EPA received no comments in response to this fact sheet.

On August 26, 2008, the RPM met with a Hammond Times reporter, and prOVided an explanation and tour of the cleanup operations.

On December 1, 2008, EPA sent a copy of the draft Third Five-Year Review Report to the City of Gary, Department of Environment, and to the Chicago-Gary Airport. EPA received no comments from these parties.

Document and Data Review

Documents used for preparation of this report are listed in the attached update to the Administrative Record for Midco I. EPA staff also used documents previously added to the Administrative Record, especially: the ROD Amendment; 1998 Five-Year Review Report; Soil Treatment Design/Build Report Alternative Remedy, Revision ~If, Midco I


and Midco II Superfund Sites, ENVIRON, July 2003; the Second Five-Year Review Report, and the ESD#3.

On-site Inspections since Last Five-Year Review

The Midco I site has been periodically inspected since the second five-year review. The results of these inspections are summarized in Table 4 at the end of this report.

Interviews

The RPM is in regular communication with technical staff of ENVIRON, LFR, and IDEM regarding the site O&M and monitoring. During several site inspections, the RPM met with the ENVIRON site operator and discussed operation of the treatment systems. On January 28,2009, the RPM called Dave Roti, who owns SSF Repair, 1356 Blaine St., which is the property adjacent to the southern boundary of Midco I. The RPM described the operations at Midco I, and asked whether he noticed any problems. He said, no that he had not even noticed any odor. He said that he may be interested in purchasing property for yard space. I told him that the operations may be completed in three to four years, and gave him the telephone number for a contact with the MRC.

VII. Technical Assessment

Question A: Is the Remedy Functioning as Intended by the Decision Document?

This question needs to be considered separately for the different components of the remedy, as presented below.

For the groundwater pump-and-treat. and deep well injection system, the answer is YES, but there are concerns: The pump-and-treat / deep well injection system is operating in compliance with all air emission and underground injection well requirements and has been achieving adequate groundwater capture. The data indicates that VOCs and other contaminants in groundwater outside of the barrier wall are being cleaned up. On the other hand, there appears to be an off-site component of the arsenic, cyanide, sulfide, iron, thallium and dieldrin contamination. As a result, it may not be possible to achieve GWCALs for these contaminants. A potential concern is that the groundwater may become re-contaminated by VOCs and other contaminants after completion of the SVE and the future cessation of groundwater pumping from within the barrier wall.

For the SVE the answer is YES. The SVE system has been successful in removing an estimated 45,000 pounds of VOCs from the subsurface. Based on recent VOC removal rates, it appears that considerably more VOCs can be removed. In August 2008, ENVIRON performed interim soil vapor sampling, which indicates that Midco I soils are approaching the 97% reduction performance standard, but that the VOC contamination remaining in the soil may still present a threat to groundwater.


For access controls the answer is YES. The site fence along with the presence of operating staff is providing sufficient current protection to public health from exposure to the contaminated soil and sediments.

For sediment excavation the answer is NO. As explained in Section IV, the ROD required that after the sediment excavation, the soils in sediment areas should be below the soil CALs, but based upon existing data, these soils continue to exceed the soil CALs. As an interim measure until the final site cover is constructed, these sediment areas have been enclosed inside a fence, which effectively prevents human contact with the contaminants, but not necessarily contact by wildlife. However as explained in the Addendum to Five-Year Review Report, the wetlands affected are small in area, of low quality, and the contaminants presenting the potential risk are at levels that may be caused by background contamination in this urban and industrialized area. For those reasons, it is acceptable to delay the final action on these sediments.

For Excavation, Off-site Disposal, and Capping. These operations have not yet been implemented.

For ICs the answer is NO. EPA's IC evaluation (p. 35) found the following: the deed restrictions required in the Consent Decree are not in place on all properties where contaminants exceed the soil CALs and/or the GWCALs; the existing deed language may not be effective; it is possible for non-potable water usage to draw contaminated groundwater off-site; and existing project plans do not include IC monitoring. EPA plans to issue a letter to the MRC requesting them to address these deficiencies.

Question B: Are the Exposure Assumptions, Toxicity Data, Cleanup Levels, and Remedial Objectives Used at the Time of the Remedy Selection Still Val lid?

The remedial objectives are still valid (see Section IV). There have been no changes in the physical conditions at the site that would affect the protectiveness of the remedy.

The 1992 ROD Amendment incorporated specific requirements for soil and groundwater cleanup (soil/sediment CALs and GWCALs), for limiting contaminants in the groundwater prior to deep well injection (MACs), and for air emissions. The ROD Amendment also incorporated toxicity factors, and exposure assumptions for calculating risks for use in calculating soil/sediment CALs, GWCALs, and air emission criteria. AWQC were identified for calculating GWCALs for protection of aquatic life, and a conservative dilution factor identified to correct groundwater concentrations for dilution in surface waters. Toxicity factors for a few contaminants were updated or added in ESD#1 (dated 1/9/96) and ESD#2 (dated 11/2/99). Only the GWCALs based on MCLs are automatically updated when MCLs change.

Question 8 needs to be considered separately for the different media, as discussed below.


For Air Emissions the answer is YES: The purpose of the 3 pounds/hr limitation on emissions of VOCs as defined under the Clean Air Act is to reduce ozone formation on an area wide basis. This limitation has not become more stringent.

The 1992 ROD Amendment provides a generic procedure for calculation of CR and HI using defined exposure rate assumptions and toxicity factors. Toxicity factors were identified for 36 VOCs, 24 SVOCs, 5 pesticides, and PCBs. The procedure for modeling emissions to obtain ambient air concentrations was not defined in the ROD.

In 2005, as part of the design of the SVE system, ENVIRON developed an air model to estimate the reasonable worst case human health risks to the nearest resident. ENVIRON calculated risks using both the Consent Decree toxicity factors and updated toxicity factors (the air exposure assumptions in the 1992 ROD Amendment were found to be consistent with current procedures). These calculations demonstrated that the updated toxicity factors were not more stringent than those included in the Consent Decree.

For the MACs the answer is YES: Using an update of the evaluation procedures used in the Second Five-Year Review Report (EPA, 2004), it was determined that an update of the MACs is not necessary.

In the 1992 ROD Amendment, the HBls were identified for 183 hazardous constituents, and the MACs defined as 6.3 times the then existing HBls. Cumulative risks are not considered. The 6.3 factor provides a very conservative allowance for the protection provided by the location, monitoring and mechanical requirements of the deep well. If an MCl was available, the HBls were the MCls. Otherwise, the HBls were the more stringent of CR = 10-6 or HI = 1.0 for residential water usage. The HBl for 1,1dichloroethane was updated in ESD#1, and the HBls for a number of carcinogenic PAHs were updated in ESD#2.

The Second Five-Year Review Report includes an explanation of how it was determined that 180 groundwater monitoring parameters would be routinely monitored in the influent, including 129 that have assigned MACs. Fifty-four contaminants that have MACs are not monitored either because there is no reliable analytical method, or because they are not known to have been disposed at Midco I and were not detected in an initial round of sampling. The Second Five-Year Review Report used the following process to screen for the need to update a MAC. First the HBls were compared to either the current MCls, or, for contaminants that did not have MCls, to the October 2002, EPA Region 9, Preliminary Remediation Goals (PRGs). For compounds whose HBls are less stringent than the MCl or PRG, then 6.3 times the MCl or PRG is compared to the current contaminant concentrations in the pumped groundwater. This five-year review updates this procedure by using the September 12, 2008 Region 3 tap water screening levels (TWSls) instead of the Region 9 PRGs.


It was found that the TWSls are more stringent than the current HBl for 49 contaminants. However, the need to update the HBls was screened out for each of these contaminants for at least one of the following reasons: because they were among the contaminants that had previously been screened out of the monitoring program; because they have not been detected in the influent during the last five years; or because they were detected at concentrations much lower than the TWSls times 6.3. It is noted that the analytical methods may not be sensitive enough to detect bis(2chloroethyl)ether or naphthalene at 6.3 times the TWSlk, but it should not be necessary to develop special analytical methods for these contaminants because bis(2·· chloroethyl)ether and naphthalene are not major groundwater contaminants.

The Second Five-Year Review Report considered that the method detection limits of the approved analytical method for a number of the hazardous constituents excl3ed their MACs. EPA considers these constituents to achieve the MACs if they are not detected because they are not known to have been disposed on the Site. This report also reaffirms the conclusion in the Second Five-Year Review Report that the twelve contaminants, for which MCls have been established since 1992, do not need a MAC or to be added to the deep well or groundwater monitoring because they were unlikely to have been disposed at Midco I.

For the GWCALS the answer is NO: The following conclusion in the Second Five-Year Review Report is still valid: some of the GWCAls may need to be updated because they have potential to cause an unacceptable human health or environmental risk at the GWCAl concentration. The most reasonable time to perform this update would be when EPA reviews a petition to turn-off the pump-and-treat system.

In accordance with the ROD Amendment, GWCAls are established at the lowest of the MCls, the AVI/aC X 3.9, CR =1 X 10-5

, or HI =1.0, with the following exceptions:

if an MCl is promulgated for a contaminant and that contaminant in 81

groundwater sample is the only one having a CR ~ 1 X10-5, then for tl1at sample,

the GWCAl for that contaminant defaults to the MCl or AWaC X 3.9 whichever is less, and that contaminant is not used in the CR calculation for that: sample. if back!~round concentrations or the lowest practical detection limit is less stringent than the lowest of these values, then the background concentration or the detection limit become the GWCAL.

Updates to toxicity values used to calculate CR and HI are only relevant for contaminants that do not have MCls (unless two or more contaminants contribute to a CR ~ 1 X10-5

), and where detections exceed background and detection limit

'~ For bis(2-chloroethyl)ether, the quantitation level is 5 ug/l, which exceeds 6.3 times the screening level (0.076 ug/l); and for naphthalene, the quantitation level is 5 ug/l, which exceeds 6.3 times tile screening level (0.88 ug/l).


concentrations. In accordance with the SOW, the MCLs are automatically added or updated when they are promulgated.

In accordance with the SOW and ROD Amendment, the toxicity values for calculation of the CR and HI criteria were defined for 65 of the contaminants on the groundwater monitoring list including for 22 VOCs, 6 low-concentration PAHs, 16 other SVOCs, 5 pesticides, 14 metals, cyanide, and PCBs. These were the contaminants of most concern at the site according to the RI. Exposure assumptions were also defined. The AWQC for calculation of the GWCALs were included in the SOW and ROD Amendment for 14 metals, 3 pesticides, pentachlorophenol, cyanide and PCBs.

In the Second Five-Year Review Report, EPA evaluated whether the GWCALs need to be updated by comparing the parameter specific GWCALs (see attached Table 3-1 from the 2005 Annual Monitoring Report) to the adjusted October 2002 PRGs', to the maximum groundwater detections using 2002 data, and to background and detection limits. For contaminants that do not have GWCALs identified in the ROD Amendment, adjusted PRGs were also compared to the maximum groundwater detections, and background and detection limits. The need to update the GWCAL for a contaminant was screened out under the following conditions: if the adjusted PRGs were not significantly more stringent than the GWCALs; if the maximum groundwater concentration was less than the adjusted PRG; or if background or the analytical detection limit exceeded the GWCAL.. The contaminants that could not be screened out were: chloroethane; ethyl benzene; tetrachloroethylene; trichloroethylene; xylene; bis(2-chloroethyl)ether; 4-methlylphenol; naphthalene; n-nitroso-di-n-propylamine; methyl parathion; manganese; and hydrogen sulfide.

EPA recently updated the Region 3 TWSLs. Using adjusted TWSLs1, EPA found that

trichloroethylene could be eliminated from needing an update because the Region 3 screening level adjusted to the 10-5 risk level exceeds the MCL. In addition, there is no TWSL for chloroethane, 4-methylphenol, or hydrogen sulfide. However, the TWSLs for ethyl benzene, tetrachloroethylene, xylene, naphthalene, and manganese are more stringent than the GWCALs; and bis(2-chloroethyl)ether, n-nitroso-di-n-propylamine, and methyl parathion have no defined GWCALs. The screening of the GWCALs can not be updated using more current groundwater data because the source area groundwater has not been sampled since 2002. The impact of the SVE treatment on source area groundwater concentrations can not be fully assessed until the SVE is complete. However, the August and September soil gas data indicate that methylene chloride, trichloroethylene, and tetrachloroethylene in soil are still a threat to groundwater.

1 The PRGs are set to be protection at CR =10-6 for carcinogenic compounds. Because the GWCALs for Midco I were set at CR =10.5, the PRGs were adjusted to CR =10.5 or to the HI =1.0, whichever was more stringent.


In addition to the human health risks there is potential for a risk to biota from venting of contaminated groundwater to wetlands north and east of Midco I. This concern was addressed in the ROD Amendment by setting the GWCAL =3.9 X AWaC, if this value was more stringent than the MCLs, and the CR, and HI criteria. Current ecological risk procedures do not allow applying a simple factor to the AWaC to account for dilution in the surface water because this procedure does not take into account impacts on benthic organisms. In the 2004 five-year review, using an approach similar to evaluating the CR and HI toxicity factors, the AWaC were compared to updated benchmark values, and the following contaminants could not be screened out: xylenes; barium; manganese; and zinc. In addition, sulfide concentrations in groundwater gr,satly exceed the AWaC for hydrogen sulfide, but this AWaC was not listed in the ROD ,Ll,.mendment.

For Soil/Sediment CALs the answer is NO: This review confirms the conclusion in the Second Five-Year Review Report that a risk screening using updated toxicity factors would not change the conclusion from the 1998 Five-Year Review Report that the soil CALs were not achieved in the Midco I sediment areas, and that ecological risks need to be further evaluated if the final remedy leaves the sediments uncovered. The 1998 Five-Year Review Report identified that the soil/sediment CALs were exceeded for carcinogenic PAHs, PCBs, bis(2-ethylhexyl)phthalate, and lead. Contaminants were detected in the sediments samples at concentrations as high as: Carcinogenic PAHs 22 mg/kg; PCBs - 2.6 mg/kg; bis(2-ethylhexyl)phthalate - 19 mg/kg; lead - 621 mg/kg. These concentrations also exceed the 2002 residential soil PRGs. An ecological risk assessment conducted by Ed Karecky of the U.S. Fish and Wildlife Service for the 1998 Review also identified that concentrations of chrysene, phenanthrene, lead, manganese, chromium, copper and nickel could present an ecological risk. The most efficient time to perform this evaluation, if needed, would be in the design document for the final site cover.

Question C: Has any Other Information Come to Light that Could Call into Question the Protectiveness of the Remedy?

All known relevant information has been addressed in previous portions of this report.

Technical Assessment Summary

Access controls appear to be acceptable. The groundwater pump-and-treat / deep well injection system, is successfully containing the groundwater contamination, and is apparently helping to reduce contaminant concentrations in groundwater. The SVE has been successful in removing VOCs from soils within the groundwater barrier wall. However, achievement of the GWCALs for some contaminants may not be possible because of contamination from off-site. EPA is also concerned that the groundwater may become re-contaminated after shut-down of the SVE and dewatering within barrier wall.


Some sediments have been excavated and contained on-site, but sediments and soils remaining in the sediment areas still exceed the soil/sediment CALs, and actions to fully address these risks are being delayed until the final site cover is constructed. In the meantime human access to these soils is restricted by a fence, and ecological risks are ongoing but are considered to be minor. Additional IC work is needed to enhance the long-term protectiveness of the remedy (see p. 35).

This review determined that the air emission criteria and MACs do not need to be updated. The GWCALs and soil/sediment CALs may need to be updated to be protective of human health and the environment when the remedial actions are completed.

VIII. Issues

Table 10: Issues

Issues Affects Current Protectiveness

(YIN)

Affects Future Protectiveness

(YIN)

1. Contamination from off-site may make it impossible for pump-andtreat system to achieve all GWCALs

N Y

2. GWCALs may not be protective N Y

3. Sediment/soils remaining in sediment excavation areas exceed CALs

N Y

4. Sediment/soil CALs may not be protective N Y

5. IC work is not complete N Y

Another concern that may become an issue is that groundwater may become recontaminated after shut-down of the SVE and with the cessation of dewatering. Modifications to the remedy may be necessary to address this concern.


IX. Recommendations and Follow-up Actions

. d . A .T bl 11 . R atlons an d F oIIow-upa e ecommen ctlons

Issue Recommendations and Follow-up Actions

Party Respon

sible

Oversight Agency

Milestone Date

Affects Protectiveness (YIN)

Current Future

1,2 Evaluate and update GWCALs and other remedy revisions at the time of review of request to shut-down pumpand-treat

MRC IDEM, EPA 12/31/2010 N Y

3,4 Evaluate soillsediment CALs, and whether to cover or furl her excavate the sediments, during design for final site cover


5 File updated restrictive covenants for all necessary properties

MRC IDEM, EPA

I

12/31/2009 N y

5 Wol1< with City of Gary to assure notification of nonpotable groundwater usage near Midco I

MRC IDEM, EPA 12/31/2009 N y

5 : Ad,j IC monitoring to O&M i plan

MRC ! IDEM, EPA 12/31/2009 N Y

5 Further evaluate and implement ICs, as necessary to Hnhance the long-term protectiveness of the remedy.


X. Protectiveness Statement

The remedy protects human health and the environment in the short term because: • Fencing, deed restrictions on some properties, and on-site staff prevent human

exposure to the contaminated groundwater, soils and sediments (a City of Gary ordinance also prohibits residential usage of groundwater);

• Although wildlife can be exposed to the contaminants remaining in the sediment areas, the area affected is small, the value of the habitat is minor, and the contaminant concentrations may not exceed background; and

• Monitoring is being performed to assure that SVE emissions comply with air emission limitations, and the thermal oxidizer is being maintained to treat the air emissions, if necessary.

In order for the remedy to be protective in the long-term, the follOWing actions are needed:

• Continued restriction of access;


• Continued O&M and monitoring of the pump-and-treat system to contain the contaminated groundwater and attempt to achieve the GWCALs (Operable Unit #1 );

• Continued O&M and monitoring of the SVE system to achieve a 97% reduction and protect groundwater (Operable Unit #2);

• excavation of high metals and cyanide contamination (Operable Unit #2); • Addressing potential for re-contamination of groundwater by contaminants

remaining within the barrier wall after discontinuation of the SVE, pump-andtreat, and excavation (Operable Unit #1);

• Consideration, and if necessary, evaluation of ecological risks during design of the site cover and final sediment excavation;

• completion of sediment excavation (Operable Unit #1); • installation of the final site cover (Operable Unit #3); • update the GWCALs; • Update the soil/sediment CALs; and • full implemention and monitoring of ICs.

XI. Next Review

The next five-year review is scheduled five-years from the date of this report.


TABLE 4: EPA, Weston and IDEM Inspections of Midco I from April 2004December 2008

DATE INSPECTOR RESULTS

4/30/2004

5/17-21,

6/3/2004

6/16/2004

6/22/2004

10/19/2004

11/212004

O. Patel, Weston

T. Cagney Weston

Y. Hagiwara, Weston

O. Patel

R. Boice, EPA

O. Patel

R. Boice

O. Patel

Inspected groundwater treatment, and waste storage. Noted reduced pumping rate within barrier wall, and hiQh GC shut-downs that had not been reported to EPA.

Oversight of annual groundwater sampling. No deviations from the workplan were observed. Noted that locks need to be replaced, monitoring wells relabeled, and some pumps replaced.

Inspected groundwater treatment, and waste storage. No probl'3ms noted. Noted possible free product in EW-3 and very high TCE and vinyl chloride concentrations in EW-5.

Inspected groundwater treatment, and waste storage. Interviewed Terry Claus, ENVIRON site operator. No problems identified. Noted that GC print-out identified a MAC exceedance. According to Claus, system was shut-down and flow from EW3 reduced in response to the GC detection.

Oversight of quarterly effluent sampling. No deficiencies were noted in the sampling. Noted that that GC print out indicated that methylene chloride exceeded MAC twice on September 30,2003, and twice in October 2004.

Inspected groundwater treatment. No problems identified. NotE~d last GC reading was 19.36 ug/I of methylene chloride.

I I

516/2004 6/10/2004

T. Borman,

B. Maradkel,

M. Castillo, and

T. Carmichael, of Weston

R. Boice

T. Borman, Weston

Oversight of installation of the temporary vapor barrier. Weston noted the following concern: the grading prior to installation of the 12-mil polyethylEme liner was not smooth and had several low spots; the Health and Safety Plan was not present on-site; personal protective equipment required in the Health and Safety Plan were not being worn when Weston arrived; significant dust was being caused by trucks bringing in offsite soil. All these issues were addressed by ENVIRON after being identified by Weston, except that the grading layer continued to have low spots.

Inspected temporary vapor barrier installation, and groundwater treatment. Observed that the temporary vapor barrier appeared hummocky in the area that had not been covered. ENVIRON staff stated that the amount of water stored between the hummocks is not enough to cause a problem with the SVE system. Borman agreed that the installation was good enough for its intended purpose. Boice suggested the following: sampling of debris pile in southwest corner; address unlocked monitoring well casing on InDOT property. Claus reported that InDOT still occasionally disposes water from catch basins in the north side of their property. Boice observed no impact on property south of Midco J, and identified no problems with groundwater treatment.

6/9/2005 R. Boice

S. Ryan, Weston

O. Patel

Inspected temporary vapor barrier installation, and groundwater treatment. Identified no problems with groundwater treatment. Temporary vapor barrier installation was complete except for roadway. Observed huge debris pile on property east of site, and how impaling fence and making monitoring difficult. I

6/24/2005

6/27-301 2005

T. Carmichael T. Bradley, Weston

Oversight of annual groundwater sampling. No deviations from the site work plan or Health and Safety Plan were identified.


DATE INSPECTOR RESULTS

7/18-19/05

7/20/05

7/21-22/05

7/25-29/05

8/1-5/05

T. Walls, Weston

A. Rodriguez, Weston

Oversight of installation of SVE wells and soil gas monitoring wells. All work appeared to have been completed in accordance with approved work plans, and the Health and Safety Plan.

Oversaw SVE pilot test. No problems identified.

Oversight of SVE well and soil gas monitoring well installation. Requested more systematic decontamination.

Oversight of a pilot test to size the SVE blower. No deviations from the site work plan or Health and Safety Plan were identified, except that FlO readings were not taken because of low oxygen levels in gas from the SVE well.

Oversight of the baseline soil gas sampling. No deviations from planning documents were observed.

Pre-final inspection of SVE system. Prepared items for completion of construction. This included noting that the blowers are not rated for explosive gases, and requiring special procedures to assure that automatic shut-down occurs before gases exceeding 50% LEL reach the blowers.

Oversight of monitoring of SVE during commissioning period. No deviations from plans noted.

Inspected SVE system. Noted concern that hydrogen cyanide was detected in flow in SVE wells.

Inspected groundwater treatment, SVE, and on-site storage. Patel identified a number of minor repairs needed.

Oversee SVE monitorinq. No deviations from plans noted.

Oversee quarterly SVE monitorinq. No deviation from plans noted.

8/24/08 A. Rodriquez

7/21/05 R. Boice

Weston

8/24/05 Weston

10/27/05 N. Save, Weston

1/26/06 R. Boice

S. Ryan

4/3/06 4/5-6/06 4/11/06 4/18/06 4/25/06 5/4/06 5/11/06 5/16/06 5/23/06 6/5-7/06

T. Walls, Weston

J. Klemp, Weston

3/30/06 O. Patel

5/15/06 R. Boice

O. Patel

7/25/06 J. Klemp

8/28-29/06 J. Klemp

10/26/06 J. Klemp Oversee monthlv SVE monitorinq. No deviations from plans noted.

1/22/07 R. Boice

S. Andrews, IDEM

S. Summer, IDEM

K. Spindler, IDEM

K. Johnson, IDEM

Inspected groundwater treatment, deep well, SVE, on-site storage, and huge debris piles east of site. Observed that the debris pile in southwest corner of Midco I was not surrounded by a silt curtain. Observed that some monitoring wells northeast of Midco I were in a valley surrounded by the debris piles. Observed concerns about disposal on adjacent properties. Interviewed Claus, and Bill Bow (LFR). According to Claus, the deep well was operating at a reduced rate using a backup pump because the primary


DATE INSPECTOR RESULTS pump was not working. No problems were identified in the groundwater treatment or SVE. Provided orientation for IDEM staff, who will be replacing Weston in providing oversight support to EPA.

Inspected annual groundwater sampling, waste storage, groundwater treatment, deep well, and SVE.

Inspected groundwater treatment, SVE, on-site storage, huge debris piles east of site, and interim soil gas sampling at Midco II. The groundwater treatment was down because of a problem with the deep well pump. No problem was identified with the SVE or on-site storage. Observed that Summa canister for soil 9as sampling was being placed after the pump instead of before the pump, as provided for in sampling plans.

Inspected groundwater treatment, SVE, on-site storage, air sampling, waste storage, and deep well. No problems identified.

Inspected groundwater treatment, SVE, and on-site storage. No problems were identified

Inspected groundwater treatment, SVE, and on-site storage. No problems were identified.

Inspected groundwater treatment, SVE, and on-site storage. No problems were identified.

Inspected SVE, SVE monitorinq, on-site storaqe. No problem iclentified.

4/25/07 S. Summer

7/30/07 R. Boice

8/1/07 K. Johnson

10/23/07 R. Boice

11/6/07 R. Boice

12/19/07 R. Boice

3/25/08 R. Boice

4/28/08 R. Boice Inspected groundwater treatment, deep well, SVE, on-site storage, and huge debris pile east of site. No problems were identified other than the following: continued build-up of the debris pile east of Midco I; Claus explained that the piezomElter east of Midco I had been covered and destroyed by the debris and that it is unsafe 10 sample N wells because of the surrounding debris; high water table was makin~l some sampling difficult; and piping in the deep well building was heavily corrodEld. Claus said that the deep well piping was last replaced in 2001, and that ENVIRON plans to replace the piping using high pressure HOPE. Interviewed Bill Bow of LFR and Barbara Coughlin of ENVIRON about efforts to increase SVE rates and reduce water in SVE pipinq.

8/26/08 Rich Boice Inspected groundwater treatment, deep well, and SVE. No inconsistencies with the work plans were noted.


,1t-3O '-10

.c:

D

1STHAVENUE

'_'0..-'->1>

FENCE

11->1>,

11-,'

---

I J I

I, I

MIDCO I SITE GARY, INDIANA

0-,11->1>..• •"

J!Jo-,~II->I>

•~-,.#t-~: lm,W:1l

'3

N-'~....>I> _......11->1>

0-'0

LEGEND

-FENCE

o EXTRACTION WELL LOCATION

.. MONITORING WELL LOCATION

• PIEZOMETER LOCATION

..-115...._ 11D •PO

CONTAINMENTIBARRIER WAlL (approl(~mate location)

APPROX. SCALE (ft.) !

"" E:NVII\ON

WELL AND PIEZOMETER LOCATIONS

SCALE 1:24000

- i1/2 0 1 MILE

2000 0 2000 4000

.5 0- - CONTOUR -INTERVAL 5 FEET NATIONAL GEODETIC VERTICAL DATUM OF 1929 '". ~

JJSOURCE: U.S.G.S. 7.5 minute series (topographic) \

Highland, Indiana Quadrangle, 1991.

...-·----------------...--------------------...----.....

SITE LOCATION MAP Figure

€ ~I V I D 0 ~I MIDCO I SITE 1I~ n I~ GARY, INDIANA

Drafter: APR Date: 03/31/05 Contract Number: 21-8601AL Approved: BSK Revised:

w

~

~ :

~

!:I_I

Ii:

TABLE 1-1

UST OF PARAMETERS ANALYZED AND PROJECT-SPEC1F1C QUANTlTATlON LlM1TS MIDCO 1 AND 11 SITES

GARY, lNDlANA

Page 1 of3

Project-Specific Project-Specific Quantitation Quantitation

Limit I Limit I

Chemical (pg/L) Chemical (pg/L)

MIDCO 1AND II SITES MIDCO I AND 11 SITES

Volatile Organic Compounds Inorganic Analytes

Acetone 5 Aluminum 21 Benzene I Antimony I Bromochlororr.ethane I Arsenic 2 Bromodichlommethane I Barium 20 Bromoform I Beryllium I Bromomethane: I Cadmium I 2-Butanone 5 Calcium 5,000 Carbon disulfide I Chromium I Carbon tetrach loride I Chromium (VI) 10 Chlorobenzene I Cobalt 1 Chlorodibromomethane 1 Copper I Chloroethane I Cyanide 10 Chloroform I Iron 50 Chlorometham: I Lead 1 1,2-Dibromo-3-chloropropane (DBCP) I Magnesium 5,000 I,2-Dibromoethane (Ethylene dibromide) 1 Manganese 25 1,2-Dichlorobenzene 1 Mercury 0.2 1,3-Dichlorobenzene I Nickel 7 1,4-Dichlorobenzene I Potassium 5,000 I, I-Dichloroet lane I Selenium 2 1,2-Dichloroehane I Silver 1 I,l-Dichloroehene I Sodium 5,000 cis-I,2-Dichlol'Oethene I Sulfide 1,000 trans-I,2-Dichloroethene I Thallium 3 1,2-Dichloropropane I Vanadium I cis-I,3-Dichlol'Opropene I Zinc I trans-I,3-Dichloropropene I Ethylbenzene I 2-Hexanone 5 Methylene chloride I 4-Methyl-2-peltanone 5 Styrene I 1,1,2,2-Tetrachloroethane I Tetrachloroethene I Toluene I 1,2,4-Trichlowbenzene I 1,1,1-Trichlowethane I I, 1,2-Trichlowethane I Trichloroethene I Vinyl chloride I Xylenes (Total) 5

Notes: ~glL = micrograms per liter.

Detection limils are highly matrix dependent. Limits provided herein may not always be achievable.

ENVIRON

I

----

--

--

----

TABLE 1-1

l.1ST OF PARAMETERS ANALYZED AND PROJECT-SPECIF1C QUANTlTATlON LIMITS MIDCO 1 AND 11 SITES

GARY, INDIANA

Page 2 of3

Project-SpecijicProject-Specijic QuantitationQuantitation

Limit lLimit l

(pg/L)(pg/L)Chemical Chemical

MIDCO 1 SITE ONLY IMIDCO I SITE ONLY

Semivolatile Organic CompoundsSemivolatile Organic Compounds

2,6-Dinitrotoluene 5Acenaohthene 5 Di-n-octvl phthalate Acenaohthylene 55

Acetophenone Diphenylamine 1010 Fluoranthene 52-Acetylamine'fluorene 10

5Anthracene Fluorene5 Aramite 5Hexachlorobenzene20

5HexachlorobutadieneBenzo(a anthracene Hexachlorocyclopentadiene 5Benzo(b fluomnthene Hexachloroethane 5Benzo(k fluomnthene 5 Indeno( I ,2,3-cd)pyrene Benzoic acid 20

Benzo(~,h,i)perylene 10Isodrin5 5Benzo(a)pyrene Isophorone 5Benzyl alcohOl 2-Methylnaphthalene5 20bis(2-Chloroethoxvlmethane 2-MethvlDhenol5 5bis(2-Chloroethyl)ether 3-MethvlDhenoI5 5bis(2-Ethylhexyl)phthalate 4-Methylphenol5

Naphthalene 104-Bromophenyl phenYl ether 5 20Butyl benzyl phthalate 2-Nitroaniline5 204-Chloroaniline 3-Nitroaniline5 20Chlorobenzilale 4-Nitroaniline10

4-Chloro-3-m(,thylphenol 5Nitrobenzene5 52-Chloronaphthalene 2-Nitrophenol5 202-Chlorophenol 4-Nitrophenol5

N-Nitroso-di-n-propylamine 54-Chlorophenv l phenyl ether 5 5Chrysene N-Nitrosodiphenylamine 10N-Nitrosomorohol ine Dibenzo(a,h)anthracene 10Dibenzofuran N-NitrosoPYITolidine5

Di-n-butvl phthalate 2,2'-Oxybis( I-chloropropane) 55 203,3'-Dichlorobenzidine Pentachlorophenol5 52,4-Dichlorophenol Phenanthrene5 10PhenolDiethyl phthallte 5 102,4-Dimethylphenol Pronamide5 5Dimethyl phthalate Pyrene5

20I ,3-Dinitroberzene 2,3,4,6-Tetrachlorophenol20 1,2,4-Trichlorobenzene 54,6-Dinitro-2-methvlphenol 20

2,4-Dinitroph( nol 2,4,5-Trichlorophenol 2020 2,4-Dinitrotoluene 2,4,6-Trichlorophenol 55

"Iotes: ~g!L = micrograms per liter.

-- = PSQL not defined for this compound for this method.

1 Detection limits are highly matrix dependent. Limits provided herein may not always be achievable.

ENVIRON

i

TABLE 1-1

LIST OF PARAMETERS ANALYZED AND PROJECT-SPECIFIC QUANTlTATJON LIMITS MJDCO 1 AND JJ SITES

GARY, INDIANA

Page 3 of3

Project-Specific Project-Specific Quantitation Quantitation

Limit} Limit}

Chemical (Ilg/L) Chemical (Ilg/L)

MIDCO I SITE ONLY IMJDCO I SITE ONLY

Chlorinated Pesticides Polycyclic Aromatic Hydrocarbons

Aldrin 0.01 Benzo(a)anthracene 0.001 a-BHC 0.01 Benzo(b)fluoranthene 0.005 13-BHC 0.01 Benzo(a)pyrene 0.001 8-BHC 0.01 Chrysene 0.005 y-BHC (Lindane) 2 Dibenzo(a,h)anthracene 0.0025 a-chlordane 0.01 7,12-Dimethylbenz(a)anthracene 0.037 y-Chlordane 0.01 Indeno( 1,2,3-cd)pyrene 0.005 4,4'-DDD 0.02 3-Methylcholanthrene 0.039 4,4'-DDE 0.02 4,4'-DDT 0.02 Organophosphorous Pesticides

Dieldrin 0.005 Dimethoate 10 Endosulfan I 0.01 Ethyl parathion 10 Endosulfan II 0.02 Famphuf 21.2 Endosulfan :;ulfate 0.02 Methyl parathion 0.5 Endrin 0.02 Thionazin 10 Endrin aldehyde 0.02 Endrin ketone 0.02 Herbicides

Heptachlor 0.01 2,4-D 30 Heptachlor (:PQxide 0.01 Dinoseb I p,p'-Methoxychlor 0.1 2,4,5-T 2 Toxaphene I 2,4,5-TP (Silvex) 4

Polycblorinated Biphenyls Direct Injection Volatile Organic Compollnds

Aroclor-lOl6 0.41 1,4-Dioxane 20

Aroclor-1221 0.41 Methanol 20 Aroclor-1232 0.41 Aroclor-1242 0.41 Aroclor-1248 0.41 Aroclor-1254 0.41 Aroclor-1260 0.41

Notes: J.lg/L = micngrams per liter.

I Detection limits are highly matrix dependent. Limits provided herein may not always be achievable.

ENVIRON

1

, PillE - yeA-I? BE view

FIGUl?E t.t i l I

) 1 i

I i \

i I ,

SURVEYING, INC.

APPROX. SCH..E (ft.)

I JII o 200

FIGURE 3-1 MONITORING WELL NETWORK


.',)

/ ..,...--------------------- •:584'\ CIlI

~Ii ~--------------

A-10.1r-al

C-3lI•C-l0

-.e Io/W-I

l5IH "'lEMur

t--*"--*-~-*- - _.*1".~..:r

a MPWoLT

NOTE: 1. DRAWING BASED ON FIGURE 1 OF THE

STATEMENT OF WORK AND THE JULY, 1992 SURVEY BY WESTSHORE ENGINEERING AND

SYMBOL LEGEND:

• PROPOSED WELL LOCATION

0 MONITORING WELL LOCATION

ESTIMATED EXTENT OF HAZARDOUS SUBSTANCE MIGRATION

)( M FINAL FENCE LOCATION

I

----------------

I I I I I I I I I I I I I I I

I I I I

11250

11000

10750

10500

10250

10000

9750

D D

I I I I I

9500 9750 10000 10250 10500 10750 11000 11250

LEGEND

• Extraction Well

~ Simulated Groundwater Flowpath (Particle Tracking)

SCALE 1" =300' MIDCO FIGUREI-5

CAPTURE ZONE ANALYSIS RECALIBRATED MODEL

MilleO I SITE, GARY, INDIANA PROJECT: MIDCO I I DATE: APRIL 2006

DWG: MIDC01FIG5.SRF I BY: EPL CHECKED: SH

€NVIRON

TABLE 4-2

SUMMARY OF THE COMPARISON OF ANALYTICAL RESULTS WITH THE CLEAN-UP ACTIONLEVELS"" MIDCO I SITE, GARY, INDIANA

Page I of2

Moni/orinK

Location

Carcinogenic Risk 4 Noncarcinogenic Risk" Parameters at or Above MeL or AWQC

TotD/

IE-OJ

1E-04

OE+OO OE+OO

OE+OO

OE+OO

OE+OO

3E-04

OE+OO

4E-04

2E-05

OE+OO

3E-06

4E-04

OE+OO

2E-05

7E-06

Contributing

Parameters

Arsenic Dieldrin bis(2-Ethylhexyl)pbthalate

ChJysene Benzene

Arsenic 4,4'-DDT

Arsenic?

1,1-Dichloroethene Trichloroethene

Arsenic'

Dieldrin bis(2-Ethylhexyl)phthalate

Concentration

pglL

26.3 0.0089 J

6.6

28 0.26 J

6.1 0.0043 J

7.6

0.16 J 0.15 J

7.1

0.21 12

Total

1

0.02

0.08 0.0005

0.4

0

0.4

0.3

2

4

2

0.2

0.1

0.2

0.2

0.2

2

Contributing

Parameters

Arsenic Antimony Cyanide Vanadium Selenium Cadmium Pentachlorophenol bis(2-Ethylhexyl)phthalate

Barium Nickel Vanadium Cyanide

Thallium Manganese

Arsenic Bariwn

Barium Nickel Selenium Vanadium

Tballium Barium Cyanide

Concentration

pglL

26.3 3.8 J

90.7 15.4 3.1 J

0.64 J 19

6.6

1,360 314 77.8 36.7

7.3 J 2,010

7.6 202

1,900 J 429 J

45.8 J 26.8 J

4.2 J 268

65.5

Concentration MCL

Parameter pgIL pglL

bis(2-Ethylhexyl)phthalate 6.6 6 Pentachlorophenol 19 1 Dieldrin 0.0089 J Arsenic 26.3 10 Cyanide 90.7 200

Iron 4,110

Iron 6,260

Cyanide 23.5 J 200

Iron 4,970

Iron 4,910

Iron 6,270

Cyanide 36.7 200 Iron 4,060

Iron 30,900 Thallium 7.3 J 2

Cyanide 37.6 J 200 Iron 8,800 J

Iron 13,200

bis(2-Ethylhexyl)phthalate 12 6

Dieldrin 0.021 Cyanide 24.2 200

Iron 4,480

Dieldrin 0.014 J Cyanide 65.5 200

Thallium 4.2 J 2

AWQC

pglL

50.7 0.00741

187 20.3 3,900

3,900

20.3

3,900

3,900

3,900

20.3 3,900

3,900 156

20.3 3,900

3,900

0.00741 20.3 3,900

0.00741 20.3 156

MW-4S 6

MW-IIS

MW-IID A-1O

A-30 6

8-10 6

8-30 6

G-IO 6

G-30

H-IO

H-30 6

K-IO

K-30 6

L-IO

L-30 6

M-IO 6

M-30

Background ,Concentration

pglL

1.5

6 10.4

3,880

3,880

10.4

3,880

3,880

3,880

10.4 3,880

3,880

10.4 3,880

3,880

1.5

10.4 3,880

10.4

Exceeds

CAL.

Yes

Yes

No Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

ENVIRON

TABLE 4-2

SUMMARY OF THE COMPARISON OF ANALYTICAL RESULTS WITH THE CLEAN-UP ACTIONLEVELS·'·1 MIDCO I SITE, GARY, INDIANA

Page 2 of2

Carcinogenic Risk" Noncarcinogenic Risk" Parameters at or Above MeL or AWQC Background Exceeds

JUonitoring Contributing Concentration Contributing Concentration Concentration MCL AWQC Concentration ,

CAL.

Locatio" Total Parameters pglL Total Parameters pglL Parameter pglL pglL pglL pglL

N-IO 3E-06 0.06 bis(2-Ethylhexyl)phthalate 7.0 6 1.5 Yes Silver 1.4 J 0.468

N-30 OE+OO 0.3 No 0-10 OE+OO 2 Thallium 3.9 J Iron 8,730 3,900 3,880 Yes

Manganese 1,790 Thallium 3.9 J 2 156 Barium 217

0-30 OE+OO 0.1 Iron 5,240 3,900 3,880 Yes

P-IO 6 IE-OS Benzene7 3.7 0.4 Iron 16,800 3,900 3,880 Yes P-30 OE+OO 0.1 Iron 5,230 3,900 3,880 Yes

Q-IO 6 7E-06 0,2 Dieldrin 0.014 J 0.00741 Yes Cvanide 24.0 200 20.3 10.4

Q-30 IE-05 Dieldrin 0.011 J 0.7 bis(2-Ethylhexyl)phthalate 9.4 6 1.5 Yes bis(2-Ethylhexyl)phthalate 9.4 Dieldrin 0.011 J 0.00741

Cyanide 62.2 200 20.3 10.4 Iron 11,700 3,900 3,880

R-IO 6 9E-06 0.2 Dieldrin 0.018 J 0.00741 Yes Iron 4,870 3,900 3,880

R-30 2E-05 Dieldrin 0,023 0.4 bis(2-Ethylhexyl)phthalate 9.1 6 1.5 Yes

bis(2-Ethylhexyl)phlha\ate 9.\ Dieldrin 0.023 0.0074\ Iron 6,090 3,900 3,880

P-I IE-05 bis(2-Ethylhexyl)phthalate 26 0.5 bis(2-Ethylhexyl)phthalate 26 6 1.5 Yes

Chrysene 0.057

P-4 2E-05 bis(2-Ethylhexyl)phthalate 26 0.2 bis(2-Ethylhexyl)phthalate 26 6 1.5 Yes

Dieldrin 0.0088 J Dieldrin 0.0088 J 0.00741 Iron 5,460 3,900 3,880

Key:

~g/l ~ Micrograms per liter,

MeL = Maximum Contaminant Level. AWQC = Ambient Water Quality Criteria.

CALs ~ Clean-up Action Levels. J = The concentration is approximate due to limitations identified during the quality assura~ce review.

, All parameters detected below the background concentrations were not considered, as established in Attachment 2 of the Statement ofWork .

2 The complete validated data tables and risk calculation tables are included in Appendices E and F, respectively.

3 The quantitation limits for dibenzo(a,h)anthracene, dieldrin, and silver at nearly all locations were above their respective Clean-up Action Levels, as indicated in Table 4-3.

4 Parameters are shown only if the cumulative risks for the location are above the acceptable carcinogenic risk of 1E-05 or above the acceptable noncarcinogenic risk of 1, and: - Parameters produce individual carcinogenic risks above IE-OS, or they produce individual carcinogenic risks higher than IE-06 and their sum produces a cumulative

carcinogenic risk above IE-05; or - Parameters produce individual noncarcinogenic risks above 1, or (for parameters with the same effects) they produce a cumulative noncarcinogenic risk above 1 (refer to Appendix B).

Parameters are shown in order of risk produced for the risk columns and in the order shown in Table 4-1 for the comparison with the MCLs and AWQCs.

. , The background concentrations were obtained from Table 1 of Attachment 2 of the Midco I and II Stalement afWork ,dated June 1992.

6 This location had parameters, ex.cluding dibenzo(a,h)anthracene, dieldrin and silver, with quantitation limits above their respective Clean up Action Levels, as indicated in Table 4-3.

7 The carcinogenic or noncarcinogenic risk calculated for this location is above IE·05 or I, but it is produced by a single analyte for which an MCL has been promulgated (the list of parameters per sampling locations and risk type is included in Appendix C). In accordance to Attachment 2 of the Statement of Work, the analyte should not be included in the risk

calculation, and its clean-up action level should be the corresponding MCL or AWQC, whichever is lower.

ENVIRON

TABLE 4-2

SUMMARY OF THE COMPARISON OF ANALYTICAL RESULTS WITH THE CLEAN-UP ACTION LEVELSI.2 MIDCO I SITE

GARY, INDIANA

Monitoring

Location

Carcinogenic Risk Noncarcinogenic Risk Parameters at or Above MeL or A WQC

Total

4E-04 8E-07 OE+OO OE+OO

OE+OO

OE+OO

OE+OO

7E-04

OE+OO

3E-04

4E-04

OE+OO

OE+OO

OE+OO

OE+OO

OE+OO OE+OO

Contributing

Parameters

Arsenic5

Arsenic5

Arsenic5

Arsenic5

Concentration

(JlglL)

6.9

12.7

6.3

7.2

Total

0.26 0.00 0.00 0.00

0.63

0.25

0.40

0.39

0.32

0.22

1.5

0.00

0.00

0.31

0.43

0.61 0.54

Contributing

Parameters

Bariwn Nickel Arsenic Vanadium Cyanide Zinc Chromium (III)

Concentration

( JlglL)

1,310 154 7.2

30.9 36.4 46.6 16.0

Mercury

Iron

Cyanide

Iron

Cyanide

Iron

Arsenic

Iron Lead

Cyanide Iron

Iron

Mercury

Zinc

Iron Iron Cyanide

Concentration MCL

Parameter (Jlg/L) ( JlglL)

0.11 J 2

6,570

28.9 200

8,950

37.7 200

4,530

12.7 10

10,100 30.9

36.4 200 21,700

12,600

0.11 J 2

1,470

5,100 7,690 41.1 200

AWQC

( JlglL)

0.05

3,900

20.3

3,900

20

3,900

187

3.900 14

20.3 3,900

3,900

0.05

1,330

3,900 3,900 20.3

MW-4S MW-IIS MW-IID

A-IO

A-30

B-IO

B-30

G-IO

G-30

H-IO

H-30

K-IO

K-30

L-IO

L-30

M-IO M-30

Background ,Concentration

( Jlg/L)

3,880

10.4

3,880

10

3.880

6

3.880

10.4 3,880

3,880

3,880 3,880 10.4

Exceeds

CALs

Yes No No Yes

Yes

Yes

Yes

Yes

No

Yes

Yes

No

No

No

Yes

Yes Yes

Page I 012 ENVIRON

TABLE 4-2

SUMMARY OF THE COMPARISON OF ANALYTICAL RESULTS WITH THE CLEAN-UP ACTION LEVELS'" MIDCOI SITE

GARY, INDIANA

Monitoring

Carcinogenic Risk Noncarcinogenic Risk Parameters at or Above MeL or A WQC Background

Concen/fation 4

Exceeds

CALsContributing Concenlration Contributing Concentration Concentration MCL AWQC

Loca/ion Total Parameters ( pglL) Total Parameters ( pglL) Parameter ( pg/L) ( pglL) ( pglL) ( pglL)

0-10 OE+OO 0.24 Lead 16.3 14 Ves 0-30 OE+OO 0.12 Iron 4,660 3,900 3,880 Yes

polO OE+OO 0.08 Iron 8,840 3,900 3,880 Ves P-30 OE+OO 0.09 No

Q-IO OE+OO 0.05 Cyanide 33.5 200 20.3 10.4 Ves Q-30 OE+OO 0.73 Iron

Cyanide 7,600

74 200

3,900 20.3

3,880

LO.4 Ves

R-tO OE+OO 0.00 No R-30 OE+OO 0.11 No

P-I 3E-04 Arsenic5 6.4 0.23 No P-4 OE+OO 0.54 Iron 4,040 3,900 3,880 Ves

Notes: J.1g/L = Micrograms per liter MeL = Maximum Contaminant Level

AWQC ~ Ambient Waler Quality Criteria J = The concentration is approximate due to limitations identified during the quality assurance review

I All parameters detected below the background concentrations were not considered, as established in Attachment 2 of the Statement of Work.

2 The complete validated data tables and risk calculation tables are included in Appendices D and E, respectively.

J Parameters are shown only if the cumulative risks for the location are above the acceptable carcinogenic risk of IE-05 or above the acceptable noncarcinogenic risk of I, and: - Parameters produce individual carcinogenic risks above IE-OS, or they produce individual carcinogenic risks higher than IE-06 and their sum produces a cumulative

carcinogenic risk above 1E-05: or - Parameters produce individual noncarcinogenic risks above I, or (for parameters with the same effects) they produce a cumulative noncarcmogenic risk above I (refer to Appendix B).

Parameters are shown in order of risk produced for the risk columns and in the order shown in Table 4-1 for the comparison with the MCLs and A WQCs.

4 The background concentrations were obtained from Table 1 of Attachment 2 of the lv/ideo I and II Statement of Work, dated June 1992.

5 The carcinogenic or noncarcinogenic risk calculated for this location is above 1E-05 or 1, but it is produced by a single analyte for which an MeL has been promulgated (the list of parameters per sampling locations and risk type is included in Appendix C). In accordance to Attachment 2 of the Statement of Work, the analyte should not be included in the risk calculation. and its clean-up action level should be the corresponding MeL or AWQC, whichever is lower.

Page 2 on ENVIRON

,i /

./

/'/

//"- CENTERLINE // OF DITCH

SVE BLOWER SHED

,--------~-~~::.':'---------------------------j'-, ~-------------------- G_~~,=:

THERMAL OXIDIZE

l'IiIG2

,;i

, : , i i i i i i i ! \r'-i G INSTALLED

SVE HEADER p~~ACCESS ROADBENEATH GRA

~P-30

P-10

R-30

~-10

APPROXIMATE BARRIER WALL - ALIGNMENT

SVE PIPING ROUTE (PVC)

METAL 8" DIAMETER PIPE

ESTIMATED SVE RADIUS OF INFLUENCE

UNO WATEREXISTING GRO o EXTRACTION WELL

UNO WATEREXISTING GR~ELL-$- MONITORING

<!J EXISTING PIEZOMETER

l'IiI EXISTING STAFF GAUGE

OR EXTRACTION (SVE) SOIL VAP ® AIR INLET WELL

VAPOR MONITORING COUPLET .. (SHALLOWIDEEP)

9 CONDENSATE TRAP

- CONDENSATE COLLECTION VES~

cJ;i BUTTERFLY VALVE

t>O BALL VALVE

RY VAPOR BARRIER (1\------- TEMPORA

USIONZONE1777/1 SURFACE EXCL W COVER SOIL A LLLLI (OUTSIDE OF NE

NOTES: ED AND THERMA LOWERSH

1 LOCATIONS OF B ARE APPROXIMATE• • OXIDIZER SHOWN L SVE W

4-INCH PVC PIPING FROM INDIVIDUA 2. TO EACH HEADER.

o 10050

SCALE IN FEET

ENVIRON

SVE SYSTEM PIPIN GLAYOUT MIDCO I SITE

GARY, INDIANA

--

Sunday, September 7, 2008 AllPDJt·Trlbunll '"ROP

OPINION

Better hope Palin doesn't answer that 3a.m. callO

'n;rn

As nature abhors a vacuum, then when the moner came Into the choice of Palin -Ihe tacy of defense. I was in the a man of 72. He confronts - if ~ so does McCain abhor pre through, Palin killt'u the proJ pnlitics of it i111- and [hey Will National Guard - nothing titu unly on the b~dl'Oom ceilmg on llJ dlctatll.lity. He is not Ju~t the ect So this ticket is in agree be right. Palin's a woman. lar ilbout it. The mere fact that those nights when sleep lioes Co maverick everyone says he is ment on government waste. Palin's anti-abortion Palin's a the McCam campai~n had to not come - the fact thai dcath <:

- he is the ageless bad boy They hate it. Run owner. Palin is a mother mention this is testament to the has sneaked into the suburbs of'iii l! The glee on his face as he It is always important to and a wife and, of course, the thinness of her resume. his life. How did this happen? c introduct!d his running mate remember about John McCaUl gm'ernor of Alaskll. She 15, sig" The elephant lR the room "Where baslhe time all gone > o

u said it all He looked like an uld that he graduated way down in nlficantly, a woman of deep when it comes to McCain is hi!! to i " asked Betty Camden and >.

r::: guy who had just come into a his class at the Naval Academv. convicllon and a formidable age He is now 7"2. which is not Adolph Green in thetr lyric for 0 c nightclub with some dishy arm That wasn't because McCam is: person. She is hardly without old-nol fhal old anyway. Rut Leonard Bemstein's '·Some

~ "I' !Ieems til me lhal Sena candy: get a load of this! Only dumb or becaure he is Ja.<:)'". It achien·ment. it ;s not }'oung and he has had Other Time" No...... "'Ills have '" tor Obarna would ralh~rCII the "this" was not some ditsy was because he had a hard time But one lille in the McCain skin cancer. John Glenn. a for to be drawn up, papers signed,ill lose a war in order to.... o woman, but a governor who with rule~. You tell him to do campaign's announcement on mer Manne fighter pilot and lit proviSIOn!> made.rn win n political campaign." SoQ. handled herself With aplomb sometbing - even study hard Palin jumps out: "As the head as the proverbial fiddle, rode a Tbe will of a president IS thesaid John McCain about CII

and confidence. She was a hit. - and something In him of Alaska's National Guard and rocket into space - and then person he has chosen 10 be his ~ Barack Obama. Now, with .J .r::: .J Q. McCain has eorned the riRht recoils. This rebellious streak, as the mother of a soldier her had to abandon his first polin vice president. John McCain. much more credibIlity, Obama ~ to looked pleased. In picking which he has called juvenile self, Governor Palin under cal race when he had an acci for political and personal reacould say the same thing abuut.. McCain. Palin, he rt"minded us that he and which he now says he stands what it takes tn lead our dent in the bathtub. Life hap SODS, bas left the United States ~ --0.... I-

« o himself is a reformer. At the regrets, almost cost him his nation and she understands the pens and it can happen to the of America to Sarah Palin. At Regardless of how he lnlghr

extol Sarah Palin - smart, very least, thiS is how he likes life in that North Vietnamese Importance of supporting our young and the lit as well as the this mumenl, she seems shockZ .... Z W Cl w '0 aUractn"e, zealou~ reformer to see himself He wages war prIson camp. His jailors told Iroops "Now, that's just plain old. You want to make God ingly undeserving.

ii she is nonetheless eminently again.'!t entitlements, agalDst him what he should do: he told silly. She is only the titular laugh? Tell him your plans.:!E --CII :!E unqualified to be president of busted budgets, against lobby them what the~' could do. leader of the guard - all gov· So a person - any person Richard CollerllS a colWl'lnlstr:::0 0 = the United Stalell. That 3 a.m. Ists He abhorred S~n. Ted This sneak persists. Sarab ernor~ are And If that is what has tn emertain a certain pru for The Wushington Post. Con::::I0:: 0:: ~ call had better be a wrong Stevens' earmark for the noto Palin is a product of it. Pundits It takes to be commander in dent terror for the unexpected. faClhimat.c

~ number rIOus Bridge to Nowhere - and will read all sorrs of reasons chief, then I should bc secre- This is parricularh'the case for cohenr@washpos! com:> ';:;: :> >.z I- Z c W .... w ..'" rn .5en 0 en

o Palin pumps life into stagnant Grand Old Party~ Q. ~ ui of fessed tax-cutter and govern ered energy where spirits had deliver the message.Qj She has given (voters) the very thing

mem reformer. But attacks OIl flagged anD inspired a vi.~jml Voila. Enter Palin.c: ~ her family have been blistering Democrats have been enjoying that had become blurred Some have criticized 0 KAlHLEEN and over the top. Gllillcing arounD the conven McCain for cynically selecting ~ the past several months: hope and change.

Thus. much of the off-mic tion center in St. Paul, It was a woman only to try 10 attract lalk in St. Paul the past rew not hard to see that the GOP is former HiUary Clinton sup

t::! PARKER Qj Q) .. ~ days centered on whether she what the arena mg a need thai Isn't specifically in dire need of a transfmaon. porters. Ob\'iously, there'sCl c: .....as up to the light. Would she Pa.lindeiIvered. about leadershIp or qualifies I've heen 10 retirement villages some truth 10 that. Being a E L..: CO t

be able to make it through? What she showed was lions for office. that had fewer gray hair., and woman is part of Palin's0CO Q) a.. :;:::; Would shl! crumble? Did Palin strength, conviction, uetermi When Obama fills i.I ~tadium to Old South parti~s that were appeal, and running mates are " Srn hen Sarah Patin took. the have the stuff to withstand the nallon, confidence, a willing with tens of thousands of admir more diverse. for whatever often picked in hopes of secur"E 0 'C ~tage Wednesday night, bludgeoning scrutiny? ness to rumble and f~arle!ls" ers, rou can he ~ure that part of r~ason, the Republican Party ing a particular state or demo

C Q) u '"~ Wthe reaction o[convl:c'!l Awaiting her performance ness. No caribou caught in the the draw is the a.udience's sense has nol been able to attract ~raphic.

Z r::: a. u> U rn tioneers went beyond mere remmded me of the day 13 headlights, she. of hemg part of sornethrng new younll peopll! or minorilies in But palin bring:. more to the .92 "C Q) Q) '0 appreciation. It was gratitude. years ago when Shannon Whatever conclusions the and extraordinary. They want to numbers that reflect the main ticket than the possibility of a c And relief that thefitst Faulkner became the first pundItrr might draw from he part of the Next New ThUlg, stream Amerlca it pUl-ports to few f~male voters. She has ani>. Republican woman on a presi female cadet at South Caroh Palm's remarks, we can be fair and people feel elcvatcd in his represent. mated voters who had little

dential ticket wasn't going to na's The Citadel. Agree or not ly certain that Middle America presence. lsit tbe message nr the mes enthusiasm for the race She'"E let them dawn. No one was with the politics that propelled felt nothmg but redemption Similarly, wben Palin senJ:er? Both - and Republi has gi \·en them the very thing ::I going to be embarrassed by her ther~, women wanted her and salv:Jtion. Dozens of e brought Republican conven calis know it Behind clolled Democrats have been t'njoying

U « CI'J 0

o .fohn McCain's maverick pick. to be at lea.st competent. To be mails in my inbnx confirm as tioneers In their feet, they doors around the Twin Cities. the past several months: hope > Se\'eral days of brutal scruti fit. To make them proud. much. "Pumped·' IS the word I weren't just applauding their lalk focused on the need for and change. n~' leading up to her accept We know the history of that keep hearing. \'Ice presidential nommee; they new lemplates, new models. That's potent medicine. It'l:i ance speech had given them disappuintment. 1 suspect even Palin's role in this electIOn is were applauding themselves. Repullhcans have to communi also Mhould come With a warn.... cause to wonder Ethics ques many Democrats would con as groundhreakmg as 8arBck They were proud of her. sure, cate that they, too, care about in~ label: '·Mav cause delusions Cl ~ tions about her possible fess to a privll.te hope that Palm Obama's for the ob\'ious rea. but ther were also proud of the issues Democrats have and a false sense nf power."

Q. lDvolvement III tr~'mg to l;l"et a would do well. There aren't sons. Both have validated the themselves. Why, they had claimed as their own - educa'6 former brother-in-law fired are enlJllgh women iII hIgh pJoce.s !>est instincts of their partieg nominated a woman' cion, health and the em'irou Kathleen Parker is (J syndiCO .5 legitimate. So are critique~ of yet for us to enjoy a first and our nation. But there's It is delightful to feel good Mento They need new ideas and cated columnist. Contact hf'r atC"'l ~ .. her perfol'manct! as a ~elf-pro- woman's stumble, no matter more. Bnth alsu seem to be fill· ahout onesdf, l.1nd Palm deliv- new - younller - faces to kparker@kpurkercamN a>)(It) """ ~ Q.en C"'l CO '"

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0.. .. ; .5

co "!

-'" EPA Reviewing0 ~

0 Q. MIDCD I & MIDCD II Superfund Sites Gary, Indiana

CD '" N " U.S. EnVironmental Protection Agency, in consultation With Indiana Department of EnVironmental '" Management. is reViewing the MIDCO I and MIDCO II ~ sites to ensure the cleanup continues to protect people and the environment. The ~ law reqUires reviews at least every five years

C r-- :S ~ at srtes where the cleanup is complete but waste remains managed on-Site.:I -0 .. EPA will evaluate sIte documents, results of periodIC inspectIons and ground-water testing. Should we

find any areas of potential concern, we will work with the companies responSible for the cleanup to fiX.Q 00)

"..U ..C

them. EPA WIll issue a report on the five-year reviews by December 31.

tIP ... .;;

>

This IS the third five-year review for these sItes... Information on the MIDCO I and MIDCO II sites can be found on the web at.- G,) 'iii ~/region5/~or:

eu U::I

Gary Public LIbrary U.S. Environmental Protectron Agency, Region 5

C Co IndIana Room Records Center, seventh floor U 200 W. Fifth Ave. 77 W. Jackson Blvd,1ft

Gary, Ind, 46402 ChICago, III. 60604~ c:: .. EPA encourages public comment. Written comments should be postmarked no later than November 28, 2008.fI) .-...0 "".~

'"

Richard~ Janet Pope

i- .eu -

Q. Remedial Project Manager Commumty Involvement Coordinator .!!! Superfun~ Division (SR-6J) Superfuruj DiviSion (P-19J)

to) 'C" EPA Region 5 EPA Region 5 77 W. Jackson Blvd. 77 w., JacJ<son Blvd... ChICago, Il 60604 Chicago, Il6lJ604 - ;-

.c 312·886-4740.Q en 312-353-0626 [email protected] [email protected];:j

1ft Post·Trlbune

I-Or call toll-free, 800-621-8431, weekdays 8:30 a.m. to 4:30 tl.JI1Q. :c

~ir·~·~~ More local columnists than any olher Norlhwestlndiana Newspaper

NO.

1

2

3

4

5

6

7

DATE

03/07/89

09/27 /96

09/09/97

09/00/98

05/06/04

05/07/04

OS/26/04

OS/26/04

06/03/04

u.s. ENVIRONMENTAL PROTECTION AGENCY REMEDIAL ACTION

ADMINISTRATIVE RECORD FOR


UPDATE #6 FEBRUARY 18, 2009

AUTHOR RECIPIENT TITLE/DESCRIPTION PAGES

Environmental Midco Addendum to Public Comment Resources Trustees Feasibility Study for the Management Midco I Site North Central, Inc.

Hutchens, R., Boice, R., Letter re: Soil Gas AnalERM-North u.s. EPA ytical Data with Revised Central, Inc. Location Diagrams for the

Midco I and II Sites

Hutchens, R., Boice, R., Letter re: Semiannual Environmental u.s. EPA Soil Gas and Monitoring Resources Well Sampling Results Management for the Midco I and II

Sites

Environmental u.s. EPA Soil Sampling Report for Resources the Midco I Management

Boice, R., Hutchens, R., Letter re: Inspection of 5 u.s. EPA ENVIRON Operation and Maintenance

of Groundwater Pump and Treat Systems at the Medco I and Midco II Sites w/Attachment

Boice, R., u.s. EPA

Hutchens, ENVIRON

R., Letter re: Approval of the Revised Standard Operating

2

Procedure for Sulfide Analysis at the Midco I and II Sites w/Attachment

Hutchens, R., Boice, R., Letter re: Response to ENVIRON u.s. EPA U.S. EPA's May 6, 2004 Let

ter Concerning Operation and Maintenance at the Midco I and Midco II Site

Hayter, S. & Boice, R., Letter re: Proposed 11 R. Hutchens, ENVIRON

U.S. EPA Changes to the Extraction Rates at the Midco I Site w/Attachments

Hutchens, ENVIRON

R., Boice, R., u.s. EPA

Letter re: Proposal to Temporarily Operate MW-3D

2

as an Extraction Well at the Midco I Site

8

9

10

NO.

11

12

13

14

15

16

17

18

19

DATE

06/04/04

06/07/04

06/08/04

06/14/04

06/14/04

06/18/04

06/23/04

07/00/04

10/20/04

11/22/04

AUTHOR

Boice, R., U.S. EPA

Hayter, S., ENVIRON

Moran, F. & R. Hutchens, ENVIRON

Method, T., IDEM

Boice, R., u.s. EPA

Patel, 0., Weston Solutions, Inc.

Boice, R., U.S. EPA

Weston Solutions, Inc.


Westlake, K., u.S. EPA

RECIPIENT

Hutchens, R., ENVIRON

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Snyder, P., Federal Aviation Administration


Boice, R., U.S. EPA


U.S. EPA

Boice,. R., U.S. EPA

Snyder, P., Federal Aviation Administration

Midco I Update #6

Page 2

TITLE/DESCRIPTION PAGES

Letter re: Relocation of 2 the Midco I MAC Compliance Point, and 2-week Shut Down at Midco II Site

Ground Water Capture Model 15 Parameters and Calibration at the Midco I Site

Letter re: Baseline Sampling/Eastward Migration Sampling at the Midco I and II Sites w/Attachments

Letter re: Draft Environmental Impact Statement for the Master Plan for Potential Development at the Gary/Chicago International Airport w/Attachment

Letter re: Operation of 2 MW-3D as an Extraction Well at the Midco I Site

E-mail Message re: June 16, 2 2004 Inspection of On-going Operation and Maintenance at the Midco I and II Sites

E-mail Message re: Midco 2 I and II June 16, 2004 Operation and Maintenance Oversight Report

Remedial Action Oversight Report for Ground Water Sampling and Investigations at the Midco I and II Sites

E-mail Message re: Summary 2 of Visit to Midco I and II Sites During Quarterly Effluent Sampling

Letter re: Final Environ- 9 mental Impact Statement for the Master Plan Development Including Runway Safety Area Enhancement/ Extension of Runway 12-30 and other Improvements at the Gary/Chicago International Airport w/Attached Comments

Midco I Update #6

Page 3

NO. DATE AUTHOR RECIPIENT TITLE/DESCRIPTION PAGES

20 12/14/04 Hutchens, ENVIRON

R., Boice, R., U.S. EPA

Letter re: ENVIRON's Responses to U.S. EPA's Comments to Proposed Changes to Ground Water Extraction Rates at the Midco I Site

6

21 01/13/05 Boice, R., U.S. EPA

Hutchens, ENVIRON

R., Letter re: U.S. EPA's Approval of Proposed Changes to Ground Water Extraction Rates at the Midco I Site

1

22 04/25/05 Kennington, ENVIRON

B., Boice, R., U.S. EPA

Analytical Results of Borrow Material for Temporary Vapor Barrier Cover Soils for the SVE System Construction at the Midco I and II Sites w/Cover Letter

23 05/00/05 ENVIRON U.S. EPA 2004 Annual Ground Water Monitoring Report for the Midco I and Midco II Sites: Volume 1 (Text, Tables and Figures)

24 05/00/05 ENVIRON U.S. EPA 2004 Annual Ground Water Monitoring Report for the Midco I and Midco II Sites: Volume 2 (Appendices A-D)

25 05/00/05 ENVIRON U.S. EPA 2004 Annual Ground Water Monitoring Report for the Midco I and Midco II Sites: Volume 3 (Appendices E-H)

26 05/05/05 Hutchens, R., & B. Kennington, ENVIRON

Boice, R., U.S. EPA

Technical Memorandum No.1: Preliminary Design Submittals for the Soil Vapor Extraction (SVE) System Build at the Midco I Site w/Attachments

27 05/06/05 Boice, R., U.S. EPA

File Conversation Call Record re: Installation of Vapor Barrier at the Midco I Site

2

28 05/13/05 Boice, R., Kennington, B., Memorandum re: Midco II 2 U.S. EPA ENVIRON Final Design Report

(Revision 3), Midco I Technical Memorandum No. 1 and Midco I Inspection

29 06/00/05 U.S. EPA Public Fact Sheet: Work on Soil 4 Cleanup Plan Begins this Spring - Midco I and Midco II Sites

NO. DATE

30 06/03/05

31 06/17105

32 07/22/05

33 09/08/05

34 10/00/05

35 10/07/05

36 10/14/05

37 10/20/05

38 11/00/05

AUTHOR

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Kennington, B., ENVIRON

Berman, M., U.S. EPA


Kennington, B. & R. Hutchens, ENVIRON

Moran, F. & B. Kennington, ENVIRON

Boice, R., U.S. EPA

Surface Construction Corp.

RECIPIENT


Moran, F., ENVIRON

Boice, R., U.S. EPA

Junk, T., Office of the Attorney General

U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA


ENVIRON

Midco I Update #6

Page 4


Letter re: Approval of the Proposed Layout and Design of the Midco I SVE System

2

E-mail Message re: Approval of Modification to Ground Water Sampling Standard Operating Procedure for the Midco I and Midco II 2005 Annual Sampling Event w/AtTachments

3

E-mail Message re: Suppleto Health and Safety Procedures at the Midco I and II Sites

1

Letter re: Transmittal of the Signature Copy of the Stipulated Order to Amend Statement of Work for the Consent Decree in the Midco Matter (Unsigned)

Remedial Action Oversight Report for SVE and Air Sparging Well Installation at the Midco I and II Sites

Letter re: Field Sampling Procedures for Baseline and Confirmation Soil Vapor Sampling at the Midco I and Midco II Sites w/Attachment

Letter re: Modification of Exclusion Zones at the Midco I and Midco II Sites

4

Letter re: Midco I and Midco II Field Sampling Procedures for Soil Vapor Sampling, Modification of Exclusion Zones, Midco I Technical Memorandum 3 and Midco II Schedule w/Attachments

Report of 2005 Mechanical Integrity Testing and Ambient Reservoir Pressure Monitoring at the Midco I and II Sites

NO.

39

40

41

42

43

44

45

46

47

48

DATE

11/00/05

12/00/05

12/08/05

12/14/05

01/00/06

01/00/06

01/03/06

01/11/06

01/17/06

01/23/06

AUTHOR





JG Innovation, LTD



Boice, R., u.S. EPA


Rzeznik, D., U.S. EPA

RECIPIENT

U.S. EPA

U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA

ENVIRON

U.S. EPA

Draschil, S., IDEM


Boice, R., U.S. EPA


Midco I Update #6

Page 5


Remedial Action Oversight Report for Ground Water Sampling at the Midco I and II Sites

Remedial Action Oversight Report for Installation of Temporary Barrier Layer at the Midco I and II Sites

Letter re: Updated Project 4 Organizational Charts for the SVE/AS Systems at the Midco I and II Sites w/Attachments

Letter Report: Request to Shut Down Hydrogen Peroxide/ Ultraviolet Light System at the Midco I Site w/Attachments

Confined Space Entry Plan 3 for the Midco I Thermal Oxidizer w/Attached Permit

Remedial Action Oversight Report of Baseline Soil Gas Sampling at the Midco I and II Sites

Letter re: Response to 13 Nov. 22, 2005 Violation Letter at the Midco II Site w/Attachments

Letter re: Midco I Tech 3 nical Memorandum #3; Midco I and Midco II Schedule Delays; Midco I and II Monthly Progress Reports

Letter re: Review Comments 2 on Request to Shut Down HP/UV System at the Midco I Site

Letter re: Review of Re 4 sults of Tests of Midco Waste Disposal Well (WOW -1), U.S. EPA Underground Injection Control Permit No. IN-089-lI-0014 in Gary, IN

49 02/02/06 Boice, R., Kennington, B., Letter re: Midco I Pre 4 U.S. EPA ENVIRON final Inspection on January

25, 2006

50

NO.

51

52

53

54

55

56

57

58

59

DATE

02/02/06

02/07/06

02/08/06

02/14/06

02/15/06

02/28/06

03/08/06

03/10/06

03/15/06

03/31/06

04/07/06

AUTHOR

Ryan, S., Weston Solutions, Inc.

Boice, R., U.S. EPA




Boice, R., U.S. EPA

Boice, R., U.S. EPA


Boice, R.,



RECIPIENT

Boice, R., U.S. EPA


Distribution List

Boice, R., U.S. EPA

Boice, R., U.S. EPA


Service List

Hutchens, R.,

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Midco I Update #6

Page 6


Letter re: Punch List 2 Items from the Pre-final Construction Inspection of the Midco I SVE System w/Attachments

Letter re: On-site Storage 2 and Off-site Disposal of Wastes from the Midco I and Midco II Site

E-mail Message re: Equip 9 ment Drawings, Alarms & Interlocks for the Midco I SVE System w/Attachments

Letter re: Response to 9 Comments on Request to Shut Down the HP/UV System at the Midco I Site w/Attached Tables

E-mail Message re: Revised 3 Start Up Procedures for the Midco I SVE System

E-mail Message re: Midco 17 I and Midco II Waste Disposal w/Attachments

Letter re: Request to Shut 2 Down Hydrogen Peroxide/ Ultraviolet Light System at the Midco I Site

Progress Reports: (144-169) for Remedial Design/Remedial Action at the Midco I and II Sites

Letter re: Midco I and 2 Midco II Health and Safety Plan w/ Attachment

E-mail Message re: Recom- 2 mendation that HCN be Monitored at all Locations at Midco I and Midco Sites

Letter re: Response to 2 Comments - Hydrogen Cyanide Detections at the Midco i and Midco II Sites

60

I

NO. DATE

61 04/20/06

62 04/20/06

63 05/00/06

64 05/00/06

65 05/09/06

66 05/10/06

67 06/02/06

68 06/06/06

69 06/16/06

70 06/28/06

AUTHOR


Smith, R., ENVIRON

ENVIRON International Corporation

ENVIRON



Boice, R., U.S. EPA



Boice, R., U.S. EPA

07/10/06 Boice, R., U.S. EPA

RECIPIENT

Boice, R., U.S. EPA

U.S. EPA

U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA


Boice, R., U.S. EPA

Boice, R., U.S. EPA


Hutchens, R., U.S. EPA

Midco Update #6

Page 7


Letter re: Request to Discontinue Ambient Air Monitoring at the Midco I and Midco II Sites w/Attachments

E-mail Message re: Transmittal of Midco Progress Report No. 167 with Replacement Page and Additional Page Inserted

2005 Annual Ground Water Monitoring Report for the Midco I and Midco II Sites

2005 Annual Ground Water Monitoring Report for the Midco I and Midco II Sites (Revised May 2006)

Letter re: Revised 2005 Capture Zone Evaluation at the Midco I and Midco II Sites w/Attachments

Letter re: Request to 1 Temporarily Suspend Ground Water Monitoring at the Midco I and Midco II Sites

Letter re: Midco I and 3 Midco II 2005 Capture Zone Evaluation w/Attached Comments

Letter re: Response to Request to Discontinue Ambient Air Monitoring at the Midco I and Midco II Sites w/Attachments

E-mail Message re: Issues 1 Identified During the May 15, 2006 Midco I and Midco II Site Visit

Letter re: Midco I and 1 Midco II Permit Re-application Class I Non-Hazardous Injection Well

Letter re: Midco I and 2 Midco II Groundwater Monitoring and Ambient Air Sampling

71

72

NO.

73

74

75

76

77

78

79

80

81

DATE

07/18/06

07/21/06

08/02/06

08/17/06

08/23/06

09/07/06

09/11/06

10/00/06

11/00/06

11/00/06

11/00/06

AUTHOR

Boice, R., U.S. EPA





Patel, 0., Weston Solutions, Inc..

Boice, R., U.S. EPA

Surface Construction Corp.

Bates, W., U.S. EPA

ENVIRON

ENVIRON

RECIPIENT


Boice, R., U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA


ENVIRON

Clous, T., ENVIRON

Midco Remedial Corporation

Midco Remedial Corporation

Midco I Update #6

Page 8


Letter re: Construction of the Midco I Groundwater Barrier Wall and SVE System and Midco II SVE/AS System

1

Letter re: Baseline Soil Vapor Sampling at the Midco I and Midco II Sites w/Attachments

Letter re: Review of Data Validation Submitted with the Baseline Soil Vapor Sampling at the Midco Sites

1

Quarterly OMM&C and Ambient Air Progress Report No. 1 (March 2006-May 2006) for the SVE System at the Midco I Site

Letter re: HP/UV System 3 Shutdown Compliance Testing Analytical Results for the Midco I Site w/Attachments

Letter re: Review Comments 3 on the Quarterly OMM&C and Ambient Air Progress Report for the Midco I Site

Letter re: Review of Base- 1 line Soil Gas Data from the Midco I and Midco II Site

Report of 2006 Mechanical Integrity Testing and Ambient Reservoir Pressure Monitoring at the Midco I and II Sites

Letter re: Results of Tests 1 of Midco's WDW #1 (UIC Permit#IN-089-1I-0014) in October 2006

Operation, Maintenance, Monitoring, and Closure Plan for the Soil Vapor Extraction System at the Midco I Site

Construction Completion Report for the Soil Vapor Extraction System at the Midco I Site

82

Midco I Update #6

Page 9


83 11/01/06 Roy, S., File Memorandum re: Review of Midco's October 6, 2006 Ambient Reservoir Monitoring Test Conducted at the WDW#l

2

Well



Letter re: Information Submittal for the Midco I and Midco II Baseline Soil Vapor Sampling



Quarterly OMM&C and Ambient Air Progress Report No. 2 (June 2006-Aug. 2006) for the SVE System at the Midco I Site

86 11/27 /06 Patel, 0., Weston Solutions, Inc.

Boice, R., U.S. EPA

E-mail Message re: Review Comments on the Quarterly OMM&C and Ambient Air Progress Report No. 2

1

87 12/21/06 Boice, R., U.S. EPA

Kennington, ENVIRON

B., Letter re: Midco I and Midco II Operation, Maintenance, Monitoring, and Closure Plans; Construction Completion Reports, Midco I Quarterly Report No.2; Midco I SVE Operations; 2005 Annual Ground Water

2

Monitoring Report

88 01/00/07 Weston Solutions, Inc.

U.S. EPA Remedial Action Oversight Report for SVE System, Air Sparge System, and Ground Water Sampling at the Midco I and II Sites

89 01/22/07 Boice, R., U.S. EPA

Distribution List

E-mail Message re: January 22, 2007 Inspection of the Midco I and Midco II Sites

2



Quarterly OMM&C and Ambient Air Progress Report No. 3 (Sept. 2006-Nov. 2006) for the SVE System at the Midco I Site

91 03/09/07 Andrews, IDEM

S., Boice, R., U.S. EPA

Letter re: IDEM's Review of the Quarterly OMM&C Progress Report No. 3 for the SVE System at the Midco I Site

92 04/16/07 Boice, R., Coughlin, B., Letter re: Midco I and 1 U.S. EPA ENVIRON and Midco II Summa Canister

Sampling

Midco I Update #6

Page 10


93 04/25/07 IDEM File Quick Sheet for Site Midco I and Midco II Site Inspections Conducted on April 25, 2007

1



Letter re: Revised Request to Shut Down Hydrogen Peroxide/Ultraviolet Light System at the Midco I and Midco II Sites w/Attached Data Sampling

95 05/07/07 Boice, R., u.s. EPA

Hutchens, ENVIRON

R., Letter re: Request to Shut Down the Hydrogen Peroxide/ Ultraviolet Systems at the Midco I and Midco II Sites

2



Quarterly OMM&C and Ambient Air Progress Report No. 4 (Dec. 2006-Feb. 2007) for the SVE System at the Midco I Site


S., Boice, R., u.s. EPA




Annual OMM&C Progress Report No. 1 (March 2006

Feb. 2007 for the SVE System at the Midco I Site



Quarterly OMM&C and Ambient Air Progress Report No. 5 (March 2007-May 2007) for the SVE System at the Midco I Site

100 10/05/07 Boice, R., Bow, W., Letter re: Midco I and 4 U.S. EPA LFR Midco II Issues Discussed

During September 12, 2007

101 10/09/07 Coughlin, B., Boice, R., Letter re: Request to 2 ENVIRON u.s. EPA Temporarily Suspend Annual

Vapor Monitoring Point Sampling at the Midco I and Midco II Sites

102 10/22/07 Andrews, S., Boice, R., Letter re: IDEM's Review IDEM u.s. EPA of the Quarterly OMM&C

Progress Report No. 5 for the SVE System at the Midco I Site

NO. DATE AUTHOR

103 11/00/07 Bates, W., U.S. EPA

104 11/13/07 Hutchens, R., ENVIRON

105 11/14/07 Coughlin, B., ENVIRON

106 12/20/07 Andrews, S., IDEM

107 01/09/08 Boice, R., U.S. EPA

108 03/21/08 Bates, W., U.S. EPA

109 03/25/08 Boice, R., U.S. EPA

110 04/02/08 Boice, R., U.S. EPA

111 04/07/08 ENVIRON

112 04/22/08 Hutchens, R., ENVIRON

113 05/01/08 Boice, R., U.S. EPA

RECIPIENT

Claus, T., ENVIRON

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Andrews, S., IDEM

File

Andrews, S., IDEM

Hardin, E., U.S. EPA

File

Boice, R., U.S. EPA

Andrews, S., IDEM

Midco I Update #6

Page 11


Letter re: Results of 1 Tests of Midco's WDW#l (Permit #IN-089-1L-0014) in October 2007

Quarterly OMM&C and Ambient Air Progress Report No. 6 (June 2007-Aug. 2007) for the SVE System at the Midco I Site

Response to Comments Dated Oct. 5, 2007; Oct. 11, 2007; Oct. 15, 2007; Oct. 22,2007; Oct. 31, 2007 from the U.S. EPA re: the Midco I and II Sites w/Attachments


E-mail Message re: Summary 2 of December 19, 2007 Visit to the Midco Sites

Memorandum re: Review of 1 Midco's October 5, 2007 Ambient Reservoir Monitoring Test at WOW #1 Well

E-mail Message re: Summary 2 of Midco I and Midco II Site Visit

E-mail Messages re: Review 2 of VOC Sampling Procedures at the Midco Sites

Groundwater Contour Map - 1 03/07/08 Shallow Monitoring Well Network at the Midco II Site

Quarterly OMM&C and Ambient Air Progress Report No. 7 (Sept. 2007-Nov. 2007) for the SVE System at the Midco I Site

Memorandum re: Inspections 4 at Midco I and Midco II on April 28 and 30, 2008

Midco I Update #6

Page 12

NO. DATE ,AUTHOR RECIPIENT TITLE/DESCRIPTION PAGES

114 OS/05/08 Coughlin, ENVIRON


E-mail Message firmation that

re: the

Con"N U

1

Monitoring Well Cluster will no Longer be Included in any Midco I Ground Water Events

l1S OS/30/08 Andrews, IDEM



2

116 OS/30/08 Andrews, IDEM



2



Quarterly OMM&C and Ambient Air Progress Report No. 8 (Dec. 2007-Feb. 2008) for the SVE System at the Midco I Site

118 06/24/08 Coughlin, ENVIRON


Request to Shut Down the Thermal Oxidizer and Monitoring and Restart Procedures at the Midco I Site



Annual OMM&C Progress Report No. 2 (March 2007

Feb. 2008 for the SVE System at the Midco I Site



Quarterly OMM&C and Ambient Air Progress Report No.9 (March 2007-May 2008) for the SVE System at the Midco I Site



Letter re: Request to Shut Down the Thermal Oxidizer

1

and Monitoring and Restart Procedures at the Midco I Site

122 09/03/08 Bates, W., U.S. EPA

Claus, T., ENVIRON

Letter re: Approval Proposed Procedures

for for a

1

Temperature Log and Radioactive Tracer Survey in Midco WOW #1

NO.

123

124

125

126

127

128

129

130

131

132

133

134

DATE

09/08/08

09/09/08

09/12/08

09/15/08

10/00/08

10/08/08

11/01/08

11/03/08

11/03/08

11/05/08

11/05/08

11/07/08

AUTHOR

Boice, R., U.S. EPA


u.S. EPA

Andrews, S., IDEM

ENVIRON International Corporation


Environ International Corporation

Coughlin, B., ENVIRON


Boice, R., U.S. EPA

Andrews, S., IDEM


RECIPIENT

Andrews, S., IDEM

Service List

File

Boice, R., U.S. EPA

U.S. EPA

Service List

U.S. EPA

Boice, R., U.S. EPA

Boice, R., U.S. EPA

Andrews, S., IDEM

Boice, R., U.S. EPA

Service List

Midco I Update #6

Page 13


Letter re: Midco I and Midco II Five-Year Reviews

1

Progress Reports: (170-196) for Remedial Design/Remedial Action at the Midco I and II Sites

Master SL the Midco Sites

Table Run for I and Midco II

Letter re: Annual OMM&C Progress Report No. 2 for the Midco I Site

1

2008 Annual Ground Water Monitoring Report for the Midco I and Midco II Sites

Memorandum re: Progress Report No. 197 September 1-30, 2008 RD/RA for the Midco I and Midco II Sites

Report of 2008 Five-Year Mechanical Integrity Testing and Ambient Reservoir Pressure Monitoring for Midco Waste Disposal Well No. 1

Letter re: Limited Soil Vapor Sampling Event August-September 2008 for the Midco I Site

Memorandum re: Quarterly OMM&C Progress Report No. 10 June-August 2008 SVE System for the Midco I Site

E-Mail Transmission re: Midco I Thermal Oxidizer w/ Reply History

Letter re: Third FiveYear Review Report for the Midco I Site

2

Memorandum re: Progress Report No. 198 October 1-31, 2008 RD/RA for the Midco I and Midco II Sites

Midco I Update #6

Page 14



R. , Service List

Memorandum re: Progress Report No. 199 November 1-30, 2008 RD/RA for the Midco I and Midco II Sites


S. , Boice, R. , U.S. EPA

Letter re: Third Five-Year Review Reports for the Midco I and Midco II Sites

1


R. , Service List

Memorandum re: Progress Report No. 200 December 1-31, 2008 RD/RA for the Midco I and Midco II Sites


S. , Boice, R. , U.S. EPA

Letter re: Quarterly OMM&C Progress Report No. 10 June-August 2008 SVE System for the Midco I Site

2

139 01/15/09 Coughlin, ENVIRON

B. , Boice, R. , U.S. EPA

E-Mail Transmission re: TCE in the Midco I Influent w/ Reply History

1


R. , Boice, R. , U.S. EPA

Memorandum re: Quarterly OMM&C Progress Report No. 11 September-November 2008 SVE System for the Midco I Site

TABLE 3-1

PARAMETER-SPECIFIC CLEAN·UP ACTION LEVELS AND ASSOCIATED PARAMETERS 1

MJDCO 1 AND 11 SITES GARY, INDIANA

Page J of2

Parameter-Specijic

Background Project- AWQCxF CAL'

Specific Risk-Based Risk-Based

Parameter MidcoI MidcoII QL MCL MidcoI Midcol1 Care. Noncarc. Midcol MidcoIJ

Volatile Organic Compounds

Acetone 6.9 5 3,240 3,240 3,240

Benzene 0.04 I 2.69 2.69 2.69

2-Butanone 5 588 588 588

Carbon tetrachloride I 5 0.6 23 I 1

Chlorobenzene I 100 48.8 48.8 48.8

Chloroform 1 1.2 324 1.2 1.2

1,2-Dibromo-3-chloroPTOpane I 0.2 1 I 1,2-Dibromoethane I 0.05 I I

I,Z-Dichlorobenzene I 600 398 398 398

IA-Dichlorobenzene I 75 13.5 7,187 13.5 13.5

I,I-Dichloroethane I 138 138 138

1,2-Dichloroethane I 5 0.86 I I I,I-Dicbloroethene I 7 0.074 290 I I cis-I,2-Dichloroethene I 70 70 70

trans-l,2-Dichloroethene 0.16 6.1 I 100 100 100

l,2-Dichloropcopane I 5 4.76 4.76 4.76

Ethvlbenzene I 700 3,240 700 700

Metbvlene chloride 1.3 1.9 I 5 6.27 1,830 5 5

4-Methvl-2-uentanone 5 1,620 1,620 1,620

Styrene I 100 100 100

1,1,2,2-Tetrachloroethane I 0.39 I I

Tetrachloroethene I 5 5.27 324 5 5

Toluene I 1,000 4,990 1,000 1,000

1,2,4-Trichlorobenzene 1 70 29.4 29.4 29.4

1,1,1-Trichloroethane I 200 1,500 200 200

I,l,2-TrichJoroetbane I 5 1.37 129 1.37 1.37

Trichloroethene I 5 6.23 5 5 Vinvl chJoride 1.32 2.2 I 2 0.1 1.32 2.2 Xylenes (total) 5 10,000 3,860 3,860 3,860

Semivolatile Organic Compounds Benzoic acid 20 129,450 129,450 129,450

bis(2-Ethvlhexvllohthalate 1.5 5 23.1 647 6 6

Butvl benzvl ohlhalate 5 6,472 6,472 6,472

4-Chloroaniline 5 9.25 129 9.25 9.25 Di-n-butvl Dhthalate 0.3 5 3,236 3,236 3,236 2,4-DichloroDhenol 20 97.1 97.1 97.1 Diethvl ohthalate 5 25,890 25,890 25,890 Hexachlorobenzene 5 I 5 5 Hexachlorocyclopentadiene 5 50 50 50 Isonhorone 5 78.9 4,854 78.9 78.9 2-Methvlnhenol 5 1,618 1,618 1,618 4-Methvlnhenol 5 1,618 1,618 1,618 Nanhthalene 10 12,945 12,945 12,945 Nitrobenzene 5 4.46 5 5 n-Nitrosodinbenylamine 0.26 5 66.0 66.0 66.0 Pentachlorophenol 20 50.7 971 20 20 Phenol 10 19,417 19,417 19,417

Chlorinated Pesticides Aldrin 0.01 0.019 0.971 0.019 0.019 y-BHC (Lindane) 2 0.2 2 2 Chlordane 0.01 2 0.249 1.62 0.249 0.249 4,4'-DDT 0.02 0.952 16.2 0.952 0.952 Dieldrin 0.005 0.00741 0.0202 1.62 0.00741 0.00741 Endrin 0.02 2 0.00897 9.71 0.02 2 Heptachlor 0.01 0.4 0.4 0.4 Heptachlor expoxide 0.01 0.2 0.0148 0.0137 0.0148 0.0137 Methoxychlor 0.1 40 40 40 Toxaphene I 3 3 3

Polychlorinated Biphenyls Polychlorinated biphenyl compounds 0.41 0.5 0.0546 0.0420 0.41 0.41

ENVIRON

-- -- -- ---- -- -- ---- -- ---- -- -- ---- -- ---- -- --

-- -- -- ------ -- --

-- -- -- --

-- ---- --

----

------

-- ---- -- -- --

-- -- ----

---- -- ---- -- ---- -- --

-- ---- --

TABLE3-I

PARAMETER-SPEClFlC CLEAN-UP ACTION LEVELS AND ASSOCIATED PARAMETERS I MIDCO I AND 11 SITES

GARY, INDIANA

Page 2 of2

Project-Background

Specific

Parameter QLMidcoJ Midco11

Polycyclic Aromatic Hydrocarbons

Benza a anthracene 0.001

0.005Benzo(b fluoranthene 0.001Benzo(a)pYTene

Chrysene 0.005

Dibenzo a,h)anthracene 0.0025 Indeno( 1,2,3-cd)pyrene 0.005

Herbicides

2,4-D - -- 30 I Dinoseb - I -- I I I 2,4,5-TP (Silvex) -- -- 4

Inorganic Aoalytes

Antimonv 15.1 107

0.15 7.5 7.5

25.2 158

15,300 5.6 464

0.25 12.3

4.6

1,470

I Arsenic 6 2 Bariwn 118 20 Beryllium .- I Cadmium I-Chromium (1I1) 8 I Chromium (VI 8 10 CooDer .- I Cvauide lOA 10 Iron 3,880 50 Lead 1 Mane.anese 1,400 25 Mercury 0.2 Nickel 58 7 Selenium 2 Silver I Thallium 3 Vanadiwn 4.33 I Zinc I

MCL

0.2

-

70 I 7 I

50

6

10 2,000

4

5 100

_. 200

2

50

2

-187

-20.7 4.68 858

42.9 50.7 20.3 3,900 13.7

-0.0468

655 137

0.468

156

1,330

AWQCxF

Midcol Midco11

- ----_. -

-----

-.I

173

19.1

10.4 2,010 39.6 120 18.7

3,600 53.6

0.0432 1,580

126 0.432

144

3,160

Rislv-Based

Care.

2.81

0.0938

0.0281

2.81 0.0281

2.81

I -..

0.18

.

_.

_.

Risk-Based

Noncarc.

I -

12.9

32.4 1,620

162

32.4 32,400

162 .

647

6,470 9.71 647

97.1

2.27

227 6,470

Parameter.Specific CAL'

MidcoJ Midco11

2.81

0.0938 0.0938

0.0281

2.81

0.0281

2.81

0.0281

2.81 0.0281

2.812.81

70 70

7 I 7 50 50

I I

6 6

6 15.1

1,620 1,620

4 4

4.68 5 100 100

42.9 39.6 50.7 120

20.3 158

3,900 15,300

13.7 53.6

6,470 6,470

0.20 0.25

647 647

50 50

I 4.6

3 3

227 227 1,330 3,160

Notes: MeL = Primary maximum contaminant level, from 40 CFR 141, as of July 2002.

AWQC x F = Site-specific chronic ambient water quality criteria (AWQC). equal to the federal AWQC for protection of aquatic life times the site·specific factor F; from Table 2 of Attachment 2 of the Midco I and nStatement of Work, dated June 1992.

Background = Site-specific background ground water concentrations; from Table 1 of Attachment 2 of the Midco I and II Statement of Work, dated June 1992.

QL = Quantitation Limit. Carc. = Carcinogenic risk-based concentration equivalent to IE-05 carcinogenic risk for the individual parameter.

Noncarc. = Noncarcinogenic risk-based concentration equivalent to a noncarcinogenic hazard index of I for the individual parameter. CAL = Clean-up Action Level.

-- = Value not specified or not calculated.

I All concentrations are given in micrograms per liter.

2 Lowest value between the MCL, AWQC, and the risk-based concentratlons calculated for tbe individual parameter, but not less than the projectaspecific detection limit or the site-specific background concentrations.

ENVIRON

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