Vapor Intrusion Guidance Comments & Database

USEPA’s (OSWER) 11/03 Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils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

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

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 Q&A and Comments, 20 min

Status of OSWER’s 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)

VI Guidance Workgroup [& contributors]

OSWER’s draft-Vapor Intrusion Guidance

Paul Johnson, ASU Todd McAlary, GeoSyn Ian Hers, UBC/Golder

Andrew Fan, R3 David Bennett, OERR Dave Mickunas, ERTDebbie Newberry, OSWER Diane Groth, NJDEP Dom. Digiulio, ORDCraig Dukes, SC Edgar Ethington, CO Frank Kover, ORDHelen Dawson, R8 Henry Schuver, CAPB Jeff Crum, MIJohn Boyer, NJDEP Jim Weaver, ATH Matt Hale, OSWMatt Straus, OSWER Paul Locke, MADEP Ray Cody, R1Richard Mattick, OUST Ronald Mosley, RTP Sheila Gaston, CO

Stiven Foster, ORD Tom Aalto, R8

Robbie Ettinger, Shell Leslie Hay-Wilson, SageR David Folkes, Env-GrpBlayne Hartman, HP Labs Marcia Bailey, R10 Pat Vanleeuwen, R5A. Guiseppi-Elie, Dupont Elsie Patton, CTDEP Vic Kremsec, BPTom McHugh, API Bill Wertz, NYDEC Craig Mann, EQM

Intent? OSWER’s 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

Tier 1- Primary Screening OSWER’s draft-Subsurface Vapor Intrusion Guidance

“quickly identify … any potential exists”

Q1 Volatiles? Q2 Buildings? Q3 Immediate concerns?

If … not … “incomplete” … proceed to Secondary Screening

Tier 2- Secondary Screening OSWER’s 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

Secondary Screening (Q4 & Q5) OSWER Vapor Intrusion Guidance

Not applicable if ‘Precluding Factors’:

- Shallow sources (< 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)

Calculation of Soil Gas and Groundwater Target Screening Levels

Select indoor air target screening level.

AF = 0.1

AF = 0.001

AF = 0.01

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

Slide by Dr. H. Dawson

Conceptual Site Model for Vapor Intrusion

Draft-RCRA VI Guidance, 2001

1/101/1 1/101/10

1/100

1/1,000

‘deep’

groundwater (>5’ bf)

1-/1 1-/1 1-/1

(-)

Ques. 4 VI Guidance Attenuation Factors

Q4 Generic Screen

Secondary Screening (Q5) OSWER Vapor Intrusion Guidance

Q5: Do media concentrations exceed semi-site specific criteria? (Table 3 (a, b ,c))

‘canned’ J&E model-based conservative model input

parameters (all, but) Soil type: sand – loam Depth to contamination:

1 – 30 meters

Attenuation factor: (SG & GW specific)

Tier 3 – Site-Specific Assess. OSWER’s 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 don’t 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”

Appendices OSWER’s 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: J&E Model “Considerations” H: Community Involvement I: “Background”

Thank You for Comments

VanCantfort, PhD Wisconsin, DNR New Jersey, DEPC. Public En. Oversight RCAP APIAlabama, DEM Michigan, DEQ Calf. DTSCIndiana, DEM Schmidt, PhD McAlary, GeoSynUSWAG DOE Montana, DEQPenn., DEP Calf. RWQCB Ohio, EPAACC Geyer, SCS Oklahoma, DEQASTSWMO Alabama, DOT DODMaine, 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.

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