VI Draft Guidance: Overview of Comments to November, 2002 OSWER VI Guidance

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VI Draft Guidance Overview of Comments to
November, 2002 OSWER VI Guidance

• Michael Sowinski
• DPRA, Inc.

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Presentation Overview

• Overview the Major Points By Commenters
• Comments Organized By
• Generally Applicable Comments
• Tier I Comments
• Tier II Comments
• Tier III Comments
• Appendices
• Summarize Primary Issues Raised

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Overview of Comments Provided

• 30 Commenters
• 18 Government (Federal State)
• 4 Industry Trade Associations
• 7 Consultants
• 1 Public Interest Group
• 6 EPA Supporting Documents
• Widely Ranging Comments
• Available on E-Docket

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Generally Applicable Comments

• Many Praises for the Effort
• Guidance is Overly Conservative
• Guidance is Overly Complex
• Guidance is Over/Under Prescriptive
• VI Guidance will Cause Cleanup Delays
• VI Guidance will Delay EI Attainment

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Generally Applicable CommentsRisk
Assessment/Risk Management Issues

• Use of Phrase Pathway Incomplete vs. Complete
  w/Acceptable Risk is Confusing
• Use of OSHA PELs for Occupational Setting!
• Appropriateness of the MCL Floor
• Incremental vs. Cumulative Risk
• Hazard Quotient of 0.2 vs. 1.0.

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Generally Applicable CommentsRisk
Assessment/Risk Management Issues (cont.)

• Indoor Sources Background Contamination!
• Procedures to Discriminate Needed
• Generic AFs Do Not Account for Background
• Guidance Should Provide Citations for Available
  Background Data (Background Floor)
• Tables 2 and 3
• Acceptable Risk? (10-4 10-6)
• Ever-Changing Toxicology Demands Living Tables.
• Extrapolated vs. Non-Extrapolated Values
• Short Term vs. Long Term Exposure
• Detection Levels vs. Risk Targets for Air and
  Groundwater

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Generally Applicable CommentsScope of Guidance

• Applicability to Petroleum Hydrocarbons
• Citing Biodegradation, Deal with Petroleum
  Hydrocarbons Separately
• UST Sites vs. Petroleum Hydrocarbon Sites
• Do Not Endorse RBCA Guidance
• Table 1 COC List
• Inclusion of Additional COCs
• COC List vs. CAA Hazardous Air Pollutants
• COC List vs J E Spreadsheets
• Retroactive Application at CERCLA/VCP Sites
• Relation to CERCLA Risk Assessment

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Generally Applicable CommentsPurpose of Guidance

• Need for Guidance on Additional Items
• More Advice on Air Sampling
• Prepare a Background Source Study
• Advice on Delineating Risk, Cumulative Risk, and
  Triggers for Cleanup Actions
• How to Measure for Model Inputs
• Guidance Should be Less Prescriptive
• Risk Management vs. Risk Assessment

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Tier 1 Comments

• Precluding Factors
• Ask Once
• More Justification Needed/Suggestions Provided
• CSM Should Include Breakdown Products
• Should Consider Presence of Vapor Barriers
  During Tier 1
• The Use of Existing vs. New Data Need Clarity
• What Qualifies as Reasonable Estimate of GW

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Tier 1 Comments

• 100 Foot Lateral and Vertical Limits
• Future Development Issues
• Design and Enforcement of Institutional Controls
• Guidance Lacks Direction on This
• Immediate Action
• Focus on Background Contamination
• Use of Engineering Controls Needs Clarity

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Tier 2 CommentsGeneral

• Use of Bulk Soil Samples
• Joint Use of Soil Gas Groundwater Samples
  Need Clarity.
• Generic vs. Chemical Specific AFs

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Tier 2 CommentsEmpirical AFs

• Generic AFs are Over Conservative
• Utilize Max. vs. Mean IA Data
• Site Selection Bias Exists
• Does Not Adequately Account for Background
• Henrys Law Based Equilibrium Assumption
• Suggestions Provided for Alternative AFs
• More Field Data Required (Data Quality Guidelines
  Should Be Imposed On Submitting Agency)
• Same Database to Create Validate Data

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Tier 2 CommentsJEM Inputs for Figure 3

• More Details Needed to Support Figure 3
  Development
• Figure 3 Should Assume 10C not 25C
• Figure 3s 5L/min Assumption Conflicts
  w/Diffusive Transport Assumption
• Figure 3 Should Consider More Soil Types
• Construction Characteristics Not Properly
  Accounted For Commercial Building AFs Vary
  Greatly from Residential AFs

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Tier 3 CommentsJEM Model

• Requires Sophisticated Expertise
• Need Better Rationale for Input Parameters
• Critical Parameters for JEM
• JEM Use Considerations
• Effects of Soil Sorption
• Transport Across Capillary Fringe
• Aqueous Phase Diffusion
• Presence of NAPL

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Appendix A Data Quality Assurance Considerations

• Appropriateness of the Use of the Visual Sampling
  Plan
• Practical Experience Shows That PDLs are Higher
  Than Appendix A Lists
• Explain That Entire Analyte List for Listed
  Methods Need Not Be Tested
• For TO-15, List Costs for SCAN and SIM Mode.

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Appendix B Development of A CSM

• Provide Hypothetical Site to Illustrate CSM
  Development
• Need Clarity on How To Identify and Deal With
  Sensitive Populations

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Appendix D Development of Tables 1, 2, and 3.

• Calculations for Acceptable Indoor Air Levels Do
  Not Match With Those Used by Region III and
  Region VI.
• Table D-1 Should List Solubility, Henrys Law,
  and Maximum Calculated Vapor Concentration
• Table D-1 Should Exclude Contaminants That Do Not
  Meet the Two-Pronged Toxicity and Volatility Test
• Table 2 Should Include Screening Values for
  Non-Residential Scenarios

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Appendix E Relevant Methods and Techniques

• Appropriateness of Sub-Slab Sampling
• Sampling Recommendations Are Not Technically
  Defensible (indoor air!, soil gas, gw, sub-slab,
  soil)
• Include Post Sampling Survey Form

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Appendix G Relevant Methods and Techniques
(cont.)

• More Advice Needed on Sampling for Model Inputs
  (i.e., soil moisture, bldng. characteristics)
• Need More Careful Accounting of Background
  Contamination
• Water Table vs. Water Column Sampling

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Summary of CommentsSteps to Success