Presentation on theme: "Site Cleanup Rules Update Alaska Forum on the Environment February 13, 2008 Bill Janes and Greg Light Alaska Department of Environmental Conservation Contaminated."— Presentation transcript:
Site Cleanup Rules Update Alaska Forum on the Environment February 13, 2008 Bill Janes and Greg Light Alaska Department of Environmental Conservation Contaminated Sites Program
What is the Contaminated Sites Program? Oversees cleanup of “legacy contamination” on land or in water from oil or hazardous chemicals Old spills Old spills Careless handling & storage Careless handling & storage Improper disposal Improper disposal Separate emergency response program.
We also develop and maintain regulations & guidance governing cleanup of contaminated sites.
Site Cleanup Rules Background Site Cleanup Rules -18 AAC Risk-based approach Risk-based approach Adopted in 1999 Adopted in 1999 Little substantive modification since Little substantive modification since Parallel cleanup process in 18 AAC 78 Regulated underground storage tanks Regulated underground storage tanks
Goal - Improve clarity, flexibility and scientific defensibility!
Cleanup Levels Found in Title 18 of the Alaska Administrative Code Chapter 75 (18 AAC 75) Look-up Tables Look-up Tables Site-specific alternative cleanup levels Site-specific alternative cleanup levels “Risk based” Based on toxicological data Based on toxicological data Mostly based on long-term exposure Mostly based on long-term exposure
Cleanup Levels Soil (Tables B1 and B2) Ingestion & Dermal Contact (Direct Contact) Ingestion & Dermal Contact (Direct Contact) Inhalation Inhalation Migration to groundwater (lowest) Migration to groundwater (lowest) Contamination in soil that could contaminate groundwaterContamination in soil that could contaminate groundwater
Cleanup Levels Groundwater (Table C) Set at drinking water levels or based on toxicological data Set at drinking water levels or based on toxicological data Surface water Based on toxicological data Based on toxicological data Primarily exposure to aquatic organisms Primarily exposure to aquatic organisms Found in 18 AAC 70; known as “water quality standards” Found in 18 AAC 70; known as “water quality standards”
Cleanup Levels Alternative soil cleanup levels Site specific conditions Site specific conditions Will not contaminate groundwaterWill not contaminate groundwater Risk AssessmentRisk Assessment Levels based on actual exposure (people & wildlife) Levels based on actual exposure (people & wildlife) “10 times” rule for groundwater Used when groundwater is not drinkable Used when groundwater is not drinkable Groundwater must already be contaminated Groundwater must already be contaminated Back-calculates to “10 times” for soil Back-calculates to “10 times” for soil
Recap - Proposed Revisions to the Site Cleanup Rules Update Table B1 to reflect most recent science Apply single statewide migration to groundwater cleanup levels to Tables B1 and B2 Repeal Table B2 aliphatic/aromatic cleanup levels Set petroleum maximum allowable levels as true caps
Recap of Proposed Revisions Repeal 10X rule for groundwater Repeal solid waste facility exemption Clarify when institutional controls may be removed Conduct general housekeeping Update guidance documents Update qualified person definition
Commenting Stakeholders Public Comment Closed Nov Received comments from the following organizations: DoD & Federal Agencies DoD & Federal Agencies Consolidated submittal from DoDConsolidated submittal from DoD FAA, Coast Guard, Corps, Navy, Air Force submitted earlier independent commentsFAA, Coast Guard, Corps, Navy, Air Force submitted earlier independent comments ADOT&PF ADOT&PF AK Miners Association AK Miners Association Solid Waste Association of North America Solid Waste Association of North America Alaska Oil and Gas Association Alaska Oil and Gas Association Municipality of Anchorage Municipality of Anchorage ConocoPhilips and Marathon Oil ConocoPhilips and Marathon Oil Several individual consultants Several individual consultants
Primary Comments Objections to modifying maximum allowable footnote for petroleum fractions Not risk based Not risk based Defeats purpose of risk assessments Defeats purpose of risk assessments Will force cleanup of sites that present little risk Will force cleanup of sites that present little risk Objections to state-wide migration to groundwater cleanup level for petroleum Not technically accurate or defensible Not technically accurate or defensible Not applicable to Arctic sites Not applicable to Arctic sites Fuel contamination in groundwater is generally due to smear zone contact, not leachate migration Fuel contamination in groundwater is generally due to smear zone contact, not leachate migration Cost-benefit not adequately considered Cost-benefit not adequately considered
Primary Comments Objections to listing propylene glycol in contaminant tables Perceived impact to aviation Perceived impact to aviation Perception that airports will become contaminated sites Perception that airports will become contaminated sites Objections to PCB migration to groundwater Calculated level of 0.3 mg/Kg too stringent Calculated level of 0.3 mg/Kg too stringent TSCA cleanup level is 1 mg/Kg TSCA cleanup level is 1 mg/Kg Objections to repeal of the GW 10X Rule Misunderstanding regarding intent Misunderstanding regarding intent
Secondary Comment Issues (not specific to proposed changes) Derivation of GRO/DRO/RRO migration to groundwater based on flawed application of model Three-phase equation for leaching to groundwater not appropriate for petroleum fractions Three-phase equation for leaching to groundwater not appropriate for petroleum fractions Concern about conditional closures No regulatory basis No regulatory basis No policy No policy Arbitrary Arbitrary
Adoption Package What are we sending to Law? Moratorium on all proposed changes that affect petroleum mixtures (Tables B2 and C) Includes soil and groundwater Includes soil and groundwater Climate zones retained Climate zones retained No change to maximum allowable footnote No change to maximum allowable footnote No change to soil water partitioning equation No change to soil water partitioning equation No repeal of aliphatic/aromatic cleanup levels No repeal of aliphatic/aromatic cleanup levels
Adoption Package Proceed with Table B1 changes with the following exceptions: Do not list glycols Do not list glycols Do not list PCB migration to groundwater Do not list PCB migration to groundwater Footnote Table B1 statewide migration to groundwater column May not be applicable on a site-specific basis May not be applicable on a site-specific basis Proceed with Table C changes Exceptions are glycols and petroleum Exceptions are glycols and petroleum Eliminate 10X rule for groundwater
Adoption Package Proceed with general housekeeping Technical updates to guidance documents Technical updates to guidance documents Reference documents and citations update Reference documents and citations update No decision yet on proposed repeal of the solid waste facility exemption Update qualified person definition
Future Initiatives Address petroleum issues separately Rethink derivation of migration to groundwater levels for GRO/DRO/RRO Rethink derivation of migration to groundwater levels for GRO/DRO/RRO Clarify risk-based approach Clarify risk-based approach Use of indicator compounds to assign risk for weathered fuels?Use of indicator compounds to assign risk for weathered fuels? Address resource degradation Address resource degradation Continue with development of the 75/78 merger Lab approval programLab approval program Procedures manualProcedures manual Integration of regulatory languageIntegration of regulatory language
Closure Policy Development Goals Follow requirements in 18 AAC Follow requirements in 18 AAC Eliminate arbitrary distinction Eliminate arbitrary distinction Reduce unnecessary stigma and perceived encumbrance Reduce unnecessary stigma and perceived encumbrance Ensure that RPs and the public are well informed about conditions for closure Ensure that RPs and the public are well informed about conditions for closure Proposed Resolution Single closure designation Single closure designation All sites have conditions All sites have conditions
Summary Three stage revision of 18 AAC 75 & 78 Stage I -Toxicity Stage I -Toxicity Current package – primarily an update of Table B1 and Table C cleanup levelsCurrent package – primarily an update of Table B1 and Table C cleanup levels Stage II - Petroleum Stage II - Petroleum Petroleum cleanup levelsPetroleum cleanup levels Leaking Underground Storage TanksLeaking Underground Storage Tanks Analytical methodsAnalytical methods
Summary Three phase revision (continued) Stage III - Process Stage III - Process ReadabilityReadability Review and approval criteriaReview and approval criteria CS Procedures ManualCS Procedures Manual Lab approval programLab approval program QA/QC and decision documents sectionQA/QC and decision documents section Independent cleanup pathwayIndependent cleanup pathway
Current Status Commissioner briefing - Completed Response to comments – 75% completed Adoption package to Law for legal review – End of February goal Lt. Gov. filing - Projected by this summer Implementation – What happens during transition?
Web Site Fact sheet Summaries and comparisons Public notices Guidance documents adopted by reference Cleanup levels spreadsheet Cleanup levels comparison spreadsheet Presentations Comment responsiveness summary (soon)
Discussion and Questions
Derivation of the MTGW Cleanup Levels Maximum contaminant concentrations that may remain in vadose zone w/o impacting gw Back-calculated from gw cleanup level using a three phase soil-water partitioning equation Variables GW cleanup level GW cleanup level DAF DAF Organic carbon/water partition coefficient Organic carbon/water partition coefficient Foc Foc Dry bulk soil density Dry bulk soil density Air and water filled soil porosity Air and water filled soil porosity Henry’s Law constant Henry’s Law constant
Table B1: Revised Soil-Water Partitioning Equation Current Equation DAF is additive (incorrect) and differs by zone DAF is additive (incorrect) and differs by zone Variable mixing zone depth Variable mixing zone depth Default dilution factor may be modified site- specifically Default dilution factor may be modified site- specifically Default attenuation factor fixed at 10 Default attenuation factor fixed at 10 Revised Equation DAF is multiplicative and applies statewide DAF is multiplicative and applies statewide Fixed mixing zone depth (5.5 meters) Fixed mixing zone depth (5.5 meters) Fixed dilution factor (due to fixed mixing zone depth) Fixed dilution factor (due to fixed mixing zone depth) Default attenuation factor (4) may be modified on a chemical-specific basis Default attenuation factor (4) may be modified on a chemical-specific basis
Table B1 Examples Direct Contact – Over 40-inch zone Contaminant Current (mg/kg)Proposed (mg/kg) PCE13013 Toluene17,0006,600 TCE75021 Total Xylenes203,00020,300