Vapor Intrusion Guidance Comments

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Vapor Intrusion Guidance Comments Database

• USEPAs (OSWER) 11/03 Draft Guidance for
  Evaluating the Vapor Intrusion to Indoor Air
  Pathway from
  Groundwater and Soils
• Presentations of Comments by
• Henry Schuver, US EPA
• Michael Sowinski, DPRA
• Robert Truesdale, RTI
• For 2003 RCRA National Meeting, Wash.DC - Aug.
  12, 2003

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Background on Henry Schuver

• MS Geology, ASU
• 17 yrs. Experience State of NJ, Consultant,
  EPA Region 2, EPA-HQ OSW since 1997
• EI Guidance (2/99) Human Groundwater
• Vapor Summit (1/00), Issue kick-off mtg.
• EIForum2000 Mtg (8/00) w/ 2-days of Vapor experts
• RCRA EI Vapor Intrusion Guidance (10/01)
• EIVapor2002 Mtg (1/02) w/ 3-days of Vapor experts
• Participant OSWER Vapor Intrusion Guidance(11/02)
• Identified as lead to OSWER Response to Comments
• Epidemiology- DrPH candidate

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This presentation is about the Comments Received

• It is NOT presenting Responses to Comments
• Quick Review of VI Guidance, H. Schuver, 10 min
• Overview of Comments, Michael Sowinski, 20 min
• Comments on Comments, Henry Schuver 20 min
• Vapor Intrusion Database, Robert Truesdale, 20
  min
• Panel for QA and Comments, 20 min

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Status of OSWERs draft-Subsurface Vapor
Intrusion Guidance

• Signed Nov. 22, 2002 (for use)
• By OSWER Assist. Admin. (AA) Marianne Horinko
• Published in Federal Register Nov. 29, 2002
• 90-day Comment Period (Nov. 29 - Feb. 27)
• Guidance, Comments, Training available at
• http//www.epa.gov/correctiveaction/eis/vapor.htm
• http//www.epa.gov/edocket RCRA-2002-033
• http//www.clu-in.org/conf/tio/vapor_021203/
• www.iavi.rti.org (should have these slides
  audio)
• Response to Comments on-going (latest is here)

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VI Guidance Workgroup
contributors OSWERs draft-Vapor Intrusion
Guidance
Paul Johnson, ASU Todd McAlary,
GeoSyn Ian Hers, UBC/Golder Andrew Fan,
R3 David Bennett, OERR Dave Mickunas, ERT Debbie
Newberry, OSWER Diane Groth, NJDEP Dom. Digiulio,
ORD Craig Dukes, SC Edgar Ethington, CO Frank
Kover, ORD Helen Dawson, R8 Henry Schuver,
CAPB Jeff Crum, MI John Boyer, NJDEP Jim Weaver,
ATH Matt Hale, OSW Matt Straus, OSWER Paul
Locke, MADEP Ray Cody, R1 Richard Mattick, OUST
Ronald Mosley, RTP Sheila Gaston, CO Stiven
Foster, ORD Tom Aalto, R8 Robbie Ettinger,
Shell Leslie Hay-Wilson, SageR David Folkes,
Env-Grp Blayne Hartman, HP Labs Marcia Bailey,
R10 Pat Vanleeuwen, R5 A. Guiseppi-Elie,
Dupont Elsie Patton, CTDEP Vic Kremsec, BP Tom
McHugh, API Bill Wertz, NYDEC Craig Mann, EQM
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Intent? OSWERs draft-Subsurface Vapor
Intrusion Guidance

• Tool
• For assessing if pathway is complete
• Subsurface contributions only
• Single pathway (single chemical) not cumulative
  at all
• For screening in (or out)
• For further consideration (or not) (I.e.,
  potential)
• Whole facilities/sites (Not for delineating
  extent)
• Use changes reevaluation
• Not regulation
• Only guidance based on current understanding
• Not requirements or obligations

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Tier 1- Primary Screening OSWERs
draft-Subsurface Vapor Intrusion Guidance

• quickly identify any potential exists
• Q1 Volatiles?
• Q2 Buildings?
• Q3 Immediate concerns?
• If not incomplete proceed to Secondary
  Screening

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Tier 2- Secondary Screening OSWERs
draft-Subsurface Vapor Intrusion Guidance

• Compare concentrations to numerical criteria
• Measured or reasonably estimated conc. (GW, SG,
  IAQ)
• Three risks levels 10-4, 10-5, 10-6 cancer (all
  HI 1)
• Q4 - Generic criteria
• Based on empirical observations to date (0.1,
  0.01, 0.001)
• Dawson VI database, media conc. as shown in
  Table 2
• Q5 Semi-site-specific criteria
• Canned J E model (w/ EPA inputs site Depth
  Soil type
• Read predicted attenuation off graph shown
  Table 3
• If not incomplete proceed to Site-Specific

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Secondary Screening (Q4 Q5) OSWER Vapor
Intrusion Guidance

• Not applicable if Precluding Factors
• - Shallow sources (lt 5ft below bldg foundation)
  
• - Crawlspace homes (w/o liners)
• - Very permeable geology
• - Significant preferential pathways
• - Sources in unsaturated zone (above the water
  table fringe?)
• - Mobile gas plumes (Landfill gas, vapor
  clouds)
• - Very low air exchange rates or v. high (neg.)
  pressure differentials
• If there
• Proceed to Tier 3 (Q6 Site-Specific Pathway)

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Calculation of Soil Gas and Groundwater Target
Screening Levels

• Select indoor air target screening level.

• Shallow soil gas screening level (SGSLshallow )
  is 10 times indoor air target screening level.
  SVSLshallow IASL 10
• Deep soil gas screening level (SGSLdeep ) is 100
  times indoor air target level. SVSLdeep IASL
  100
• Groundwater screening level (GWSL) is the aqueous
  concentration corresponding to a soil gas
  concentration 1000 times greater than the indoor
  air target level. GWSL IASL 1000/Hc

AF 0.1
AF 0.01
AF 0.001
Slide by Dr. H. Dawson
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Conceptual Site Model for Vapor
Intrusion Draft-RCRA VI Guidance, 2001
Ques. 4 VI Guidance Attenuation
Factors
(-)
1-/1
1-/1
1-/1
1/10
1/10
1/1
1/10
1/100
1/1,000 deep groundwater (gt5 bf)
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Q4 Generic Screen
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Secondary Screening (Q5) OSWER Vapor Intrusion
Guidance

• Q5 Do media concentrations exceed semi-site
  specific criteria? (Table 3 (a, b ,c))
• canned JE model-based
• conservative model input parameters (all, but)
• Soil type sand loam
• Depth to contamination1 30 meters

Attenuation factor (SG GW specific)
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Tier 3 Site-Specific Assess. OSWERs
draft-Subsurface Vapor Intrusion Guidance

• Modeling (site-specific)
• Only to identify most-likely-to-be-impacted
  buildings
• Combining complex factors, e.g., soil, depth,
  building factors
• If no problem predicted there (by approp.
  site-specific model)
• Interim (EI) determinations dont need samples to
  confirm that
• Direct measurement (confirmation, even if no
  problem expected)
• Building-specific foundation and/or indoor air
  from
• Subset of potentially affected buildings
• Before a final decision for vapor intrusion
• If using indoor air need more than one
  background

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Appendices OSWERs draft-Subsurface Vapor
Intrusion Guidance

• A Data Quality
• B Conceptual Site Model
• C Flow Charts
• D Tables 1, 2, 3
• E Methods Techniques
• F Empirical Attenuation Factors
• G JE Model Considerations
• H Community Involvement
• I Background

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Thank You for Comments

• VanCantfort, PhD Wisconsin, DNR
  New Jersey, DEP
• C. Public En. Oversight RCAP API
• Alabama, DEM Michigan, DEQ Calf. DTSC
• Indiana, DEM Schmidt, PhD McAlary, GeoSyn
• USWAG DOE Montana, DEQ
• Penn., DEP Calf. RWQCB Ohio, EPA
• ACC Geyer, SCS Oklahoma, DEQ
• ASTSWMO Alabama, DOT DOD
• Maine, DEP Kaminsky, Earthtech Casabo, Environ.
  Op.
• Sheldon, PhD Navy Dept., DOD Washington, D.Ecol.
• Supporting Documents
• US EPA Regions, 10, 3, 8 (all Risk Assessors), 2,
  9, Indoor Environ. Div.

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Next Overview of Comments

• By Michael Sowinski of DPRA
• MS-Environ. Eng. (UM), J.D. (Vermont)
• 12 yrs. Environmental Consulting
• Manages DPRA San Diego Office
• For OSW
• Manager of Comment Review
• Manager Indoor Air Vapor Intrusion db
• Moved from MD to San Diego 2 yrs ago