Transcript RCRA National Meeting

Vapor Intrusion Guidance
Comments & Database
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USEPA’s (OSWER) 11/03 Draft Guidance for
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Presentations of Comments by:
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Evaluating the Vapor Intrusion to
Indoor Air Pathway
from Groundwater and Soils
Henry Schuver, US EPA
Michael Sowinski, DPRA
Robert Truesdale, RTI
For: 2003 RCRA National Meeting, Wash.DC - Aug. 12, 2003
Background on Henry Schuver
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MS Geology, ASU
17 yrs. Experience: State of NJ, Consultant,
EPA Region 2, EPA-HQ OSW since 1997
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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
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It is NOT presenting Responses to
Comments
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Quick Review of VI Guidance, H. Schuver, 10 min
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Overview of Comments, Michael Sowinski, 20 min
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Comments on Comments, Henry Schuver 20 min
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Vapor Intrusion Database, Robert Truesdale, 20 min
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Panel for Q&A and Comments, 20 min
Status of OSWER’s draft-Subsurface
Vapor Intrusion Guidance
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Signed Nov. 22, 2002 (for use)
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By OSWER Assist. Admin. (AA) Marianne Horinko
Published in Federal Register Nov. 29, 2002
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90-day Comment Period (Nov. 29 - Feb. 27)
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Guidance, Comments, & Training available at:
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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)
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Response to Comments on-going (latest is here)
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VI Guidance Workgroup
[& contributors]
OSWER’s draft-Vapor Intrusion Guidance
Paul Johnson, ASU
UBC/Golder
Todd McAlary, GeoSyn
Ian Hers,
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
Intent?
OSWER’s draft-Subsurface Vapor Intrusion Guidance
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Tool
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For assessing if pathway is “complete”:
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For screening in (or out)
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Subsurface contributions only
Single pathway (single chemical) – not cumulative at all
For further consideration (or not) (I.e., potential)
Whole facilities/sites (Not for delineating extent)
Use changes = reevaluation
Not regulation
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Only guidance – based on current understanding
Not requirements or obligations
Tier 1- Primary Screening
OSWER’s draft-Subsurface Vapor Intrusion Guidance
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“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
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Compare concentrations to numerical criteria
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Measured or “reasonably estimated” conc. (GW, SG, IAQ)
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Three risks levels 10-4, 10-5, 10-6 cancer (all HI = 1)
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Q4 - Generic criteria
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Q5 – Semi-site-specific criteria
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Based on empirical observations to date (0.1, 0.01, 0.001)
‘Dawson’ VI database, media conc. as shown in Table 2
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’:
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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
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Select indoor air target screening level.
Shallow soil gas screening level (SGSLshallow ) is 10 times
indoor air target screening level.
SVSLshallow = IASL * 10
AF = 0.1
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SVSLdeep = IASL * 100
AF = 0.01
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AF = 0.001
Deep soil gas screening level (SGSLdeep ) is 100 times indoor
air target level.
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
Ques. 4 VI Guidance
Attenuation Factors
Draft-RCRA VI Guidance, 2001
(-)
1-/1
1-/1
1/10
1-/1
1/1
1/10
1/10
1/100
1/1,000
‘deep’
groundwater (>5’ bf)
Q4
Generic
Screen
Secondary Screening (Q5)
OSWER Vapor Intrusion Guidance
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Q5: Do media concentrations
exceed semi-site specific
criteria? (Table 3 (a, b ,c))
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‘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
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Modeling (site-specific)
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Only to identify ‘most-likely-to-be-impacted’ buildings
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If no problem predicted there –
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Combining complex factors, e.g., soil, depth, & building factors
Interim (EI) determinations don’t need samples to confirm that
Direct measurement
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(by approp. site-specific model)
(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
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A:
B:
C:
D:
E:
F:
G:
H:
I:
Data Quality
Conceptual Site Model
Flow Charts
Tables 1, 2, & 3
Methods & Techniques
Empirical Attenuation Factors
J&E Model “Considerations”
Community Involvement
“Background”
Thank You for Comments
VanCantfort, PhD
C. Public En. Oversight
Alabama, DEM
Indiana, DEM
USWAG
Penn., DEP
ACC
ASTSWMO
Maine, DEP
Sheldon, PhD
Wisconsin, DNR
RCAP
Michigan, DEQ
Schmidt, PhD
DOE
Calf. RWQCB
Geyer, SCS
Alabama, DOT
Kaminsky, Earthtech
Navy Dept., DOD
New Jersey, DEP
API
Calf. DTSC
McAlary, GeoSyn
Montana, DEQ
Ohio, EPA
Oklahoma, DEQ
DOD
Casabo, Environ. Op.
Washington, D.Ecol.
Supporting Documents:
US EPA Regions, 10, 3, 8 (all Risk Assessors), 2, 9, & Indoor Environ.
Next: Overview of Comments
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By:
MS-Environ. Eng. (UM), J.D. (Vermont)
12 yrs. Environmental Consulting
Manages DPRA San Diego Office
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Michael Sowinski of DPRA
For OSW
Manager of Comment Review
Manager Indoor Air Vapor Intrusion db
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Moved from MD to San Diego 2 yrs ago