Bill Janes and Earl CrappsBill Janes and Earl CrappsDepartment of Environmental ConservationDepartment of Environmental ConservationDivision of Spill Prevention and ResponseDivision of Spill Prevention and Response

Contaminated Sites ProgramContaminated Sites Program

Presentation Overview Site cleanup rules background

Multi-phase revision approach

Modifications effective October 8

Petroleum Issues

Audience discussion and input

Cleanup rules (18 AAC 75.325-390) developed over 10 years ago - no major changes since

Default cleanup levels in look-up tables

Risk-based approach allows for alternative cleanup levels

Similar regulations for regulated UST cleanups developed in early 1990s (18 AAC 78)

Cleanup levels in 75 adopted by referenceLab approval program in 78

Differences in terminology and procedure

Phase I - Completed• Updated Table B1 and Table C cleanup levels

• Updated several other technical requirements

• Addressed certain policy issues

• Performed housekeeping

Phase II (current) and Beyond Update technical and policy requirements

Merge 75 and 78 cleanup sections

Introduce a new QA/QC section

Develop clear and consistent submittal review and approval criteria

Phase II and Beyond Clarify regulation, procedure, and guidance

Perform regular housekeeping

Evaluate and possibly revise the petroleum fraction cleanup levels

Q&A Fact Sheet Comment response summary Summary of 2008 Proposed Changes Revised Regulations Cleanup Levels Guidance Cumulative Risk Guidance Soil Water Partitioning Equation Tech Memo Cleanup Levels Comparison Spreadsheet Regulations Update Presentation (Nov. 2008) Petroleum Cleanup Levels Discussion Paper

Changed cumulative non-cancer HI to one significant figure (325 (g) and (h)

Updated citations - ADF&G, ADNR, Standard Methods, ASTM, 40 C.F.R. (325 h and k)

“Ingestion” replaced with “Direct Contact” (340)

Cleanup level tables updated (341 and 345)• Uses Risk Assessment Information System (RAIS)• Added new chemicals to tables• Statewide migration to groundwater cleanup

level

Added new column to cleanup level tables to distinguish between carcinogenic and non-carcinogenic contaminants

Repealed the GW “10X” cleanup level option (345 (b)(2))

Clarified when the department may eliminate the use of institutional controls (375(f))

Updated regional master discharge prevention and contingency plan boundary for Western AK

Clarified definition of “carcinogen” (990 (12)

Placed definition of “risk assessment” into regulation (990(109)

Revised soil-water partitioning equation• Fixed mixing zone depth of 5.5 meters• Technical memo provides detailed discussion http://www.dec.state.ak.us/spar/csp/guidance/soil.water.part_tm.pdf

Added default Surface Area and Adherence Factors to commercial/industrial cleanup levels

Added Absorption Factor (ABS) column for chemicals that have dermal risk effects for dermal contact pathway

Added “selection of compounds for dermal absorption” section

Added PAHs to the indicator compounds table

Added table of fugitive dust COPCs

Updated compounds that exceed cancer risk standard and HQ of 1.0 at the Table C groundwater cleanup levels

• No technical basis for the petroleum maximum allowable concentrations

• Request to move the maximum allowable issue to phase 2 of the regulation revisions

• Objection to a rigid concept regarding maximum allowable concentrations

• Maximum allowable concentrations create unreasonable demand for cleanup and a marginal reduction in risk at high cost

• Request to use SOC papers to develop technically accurate and defensible migration to groundwater cleanup levels for petroleum

• Objection to applying a statewide migration to groundwater cleanup level to Arctic sites

• Objection to applying the three-phase equation to both vadose zone and saturated zone soils

• Objection to rescinding the aliphatic/aromatic cleanup levels; important scientific link to the total fractions broken

• Petroleum fraction cleanup levels do not reflect how fuels migrate in the subsurface

• Fuel contamination in groundwater generally due to smear zone contact, not leachate migration through soil

DEC considering repeal in order to simplify regulations and follow current practice

Technical foundation for the total GRO, DRO, RRO cleanup levels would remain

Option: Rename as “residual saturation levels”

• Revise to 1,000, 2,000, and 5,000 mg/kg for GRO, DRO, RRO respectively

• Add text to regulations to clarify they are screening levels only

• Indicate a risk of NAPL migration if exceededOption: Interpret literally as not-to-exceed

thresholds

Applicable to groundwater contamination

Drinking Water Program does not regulate the petroleum fractions

Creates regulatory inconsistency

Constituent based – targets individual compounds such as benzene

Risk assessment evaluation on a case-by-case basis

Subjective/arbitrary cleanup levels

TPH approach

Fuel Fractions – Cleanup levels range widely from state-to-state

Three-phased approach may be overly conservative• Above Csat - risk remains constant

Options:• Allow for 4-phase partition modeling • Allow for greater use of leaching analyses

Three- and Four-Phase Partitioning & Human Health Risk Calculations Technical Background Report (Geosphere, CH2MHill, 2005)

Current DRO and RRO ranges selected in mid-1990s as a matter of convenience• Allowed for continued use of AK 102 and

103

Ranges not consistent with TPHWG recommendations or available data

Calculated GRO groundwater cleanup is 7.3 mg/L for aromatics and 182.5 mg/L for aliphatics• Used to calculate GRO method 2 migration to

gw soil cleanup level• As a conservative measure DEC defaulted to

the calculated GRO solubility, 1.3 mg/L, for the gw cleanup level

Calculated solubility not used for DRO gw cleanup level; instead the aromatic fraction (1.5 mg/L was used)

Washington DRO Cleanup Level ( 2,000 mg/kg)

“Note that recently, the National Institute of Environmental Health Services has announced that naphthalene, a diesel fuel component, causes cancer in animals. If EPA proceeds with

development of a cancer potency factor for naphthalene, this could result in a much lower ground water cleanup level for naphthalene than is currently allowed under Method B, and consequently, a lower soil cleanup level for diesel range organics.” (Concise Explanatory Statement - MTCA Cleanup Regulations – February 2001)

Soil – Direct Contact• Butylbenzylphthalate• Endrin• Tetrachloroethene (PCE)• Trichloroethene (TCE)• Xylenes (total)

Soil – Outdoor Air Inhalation• 1,4-Dichlorobenzene• Hexachloro-1,3-butadiene• PCE• 1,2,4-Trichlorobenzene• TCE

Soil – Migration to Groundwater• Aldrin• Bis(2-ethylhexyl)phthalate• Bromodichloromethane• Butylbenzylphthalate• p-Chloroaniline• Chlorodibromomethane (also called Dibromochloromethane)• DDD• DDE• DDT• Di-n-butylphthalate• Di-n-octylphthalate• Heptachlor• Heptachlor epoxide• Hexachlorobenzene• Hexachloro-1,3-butadiene• Hexachlorocyclopentadiene• Hexachloroethane

Groundwater• Bromodichloromethane• p-Chloroaniline• Chlorodibromomethane

(Dibromochloromethane)•