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Discussion of Comments & Preliminary Plans for Responding

Discussion of Comments & Preliminary Plans for Responding. USEPA’s (OSWER) 11/03 Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils by: Henry Schuver, US EPA For: 2003 RCRA National Meeting, Wash.DC - Aug. 12, 2003.

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Discussion of Comments & Preliminary Plans for Responding

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  1. Discussion of Comments &Preliminary Plans for Responding • USEPA’s (OSWER) 11/03 Draft Guidance forEvaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils • by: • Henry Schuver, US EPA For: 2003 RCRA National Meeting, Wash.DC - Aug. 12, 2003

  2. “A Rapidly Developing Field” Footnote 2 – 2/5/99 RCRA EI Guidance • “And Reviewers are encouraged to look to the latest guidance” • Numerous Contradictory Comments • Some Structural/Procedural • Some Technical • New understanding should be used ASAP • Over & Under-conservatism should be corrected • 1-Attenuation Factors; 2-Background; 3-Workers

  3. #1 - Attenuation Factors • Q4’s 0.1, 0.01, 0.001 too conservative? • Do we even need Q4? • Q5’s Soil Type and Depth readily obtained • Growing VI database could verify • API, ACC proposed higher attenuation • Preliminary VI db evidence suggests ?? • Larger VI db is the answer … coming ? AF = 0.1 AF = 0.01 AF = 0.001

  4. E.g.,Groundwater Vapor Project - Endicott, New York – Dr. Wertz • FIGURE 1 – Thursday 12:30-2:00 Regency A • TCE Conc. - Indoor Air vs Substructure Vapor • Core and Extended Area Sampling • 05-22-03 - Phase III Unvalidated Results - DRAFT • Sanborn, Head & Associates, Inc. • 0.0 0.1 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 • Subslab Sample Results (μg/m3) • Published background indoor air concentration • range (Kurtz and Folkes, 2002), 95th %,Median • Geo. Mean, 95% UCL, Reporting Limit = 0.2 ug/m3

  5. Thursday (8/14/03) 12:30-2:00 Regency A – Wertz & McDonald, NYSDEC & DOH 10x 100x 1000x Indoor air conc. Sub-slab vapor conc.

  6. #2–Distinguishing ‘Background’ • Endicott, NY • Few points above 0.01 (subslab-indoor) due to indoor sources ? • (some >1.0; i.e., higher indoors than sub-slab) • Will time-composite samples ever help? • (i.e., Summa Canisters) Probably not • Real-time analysis is needed (Now)

  7. Techniques for Distinguishing ‘Background’ (w/ Real-time) HJS • TAGA (Trace Atmospheric Gas Analyzer) • Concentration gradients are from sources • ERT- Dave Mickunas demonstrated tech. • Tri-media concurrent samplers (subsurface, indoor, outdoor) w/ portable GC/MS • State-of-the-art out of Calf. • At least Portable GC/MC to survey home hot spots • Mobile Biological Detectors (Dogs)

  8. Using Canines in Source Detection of Indoor Air Pollutants Sandra Bird USEPA, Office of Research and Development Athens, GA

  9. Canine Scent Detection Applications

  10. Canine Scent Capabilities • Sensitivity – 0.5 ppb for some compounds • Confounding odors – dogs can detect target in the presence of confounding odors at orders of magnitude higher concentration • Multiple targets – dogs are regularly trained to detect multiple targets (up to 20) • Capable of discriminating between targets and closely related odors

  11. #3 Work places & Vapors (EI) This is the 3rd RCRA National Meeting • … where the Vapor topic has been discussed • 2002 we held an 1½ hour long session dedicated to this issue: • See www.clu-in.org/EIVapor2002 • (For slides and audio recordings) • OSHA representatives reported OSHA levels “are not protective” [tried to update in ’89] • Epidemiologic literature associating excess rates of disease with “acceptable” OSHA levels is voluminous and continues to increase (NIH)

  12. Work places - even industries’ lawyers only say: “at industrial facilities” OSHA web-site refers to chemicals in use for products ? OSHA reps. say environ. “gray area” Several industry presentations w/ same position “at industrial facilities”

  13. Work places – guidance was intended to be flexible … • And to allow good professional judgment • Original concept was one of comparative risk: • and to not trivialize our mission (i.e., call conditions “out of control” when environmental contributions are de minimus compared to known and accepted much-higher on-going industrial exposures) • Some additional expressions of guidelines and criteria may be helpful … • “in carrying out our Agency's mission to protect human health and the environment.” • [Quote from 2003 RCRA National Mtg web-site beginning with “It is a meeting with something of interest to everyone involved in”]

  14. Next: IAVI Database effort • By: Robert Truesdale • of RTI (Research Triangle Inst.) • MS Geological Sciences • 24 yrs. Environmental Consulting for EPA • Manages Geochemistry & Remediation Prog. • For OSWER • Tech. Lead – Soil Screening Guidance TBD • Risk Assessments Coal Combustion Waste, & HWIR • Tech. Lead - Indoor Air Vapor Intrusion db • Tech. Lead – VI Guidance for State of Indiana

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