EPA s Final Vapor Intrusion Guidance Introductory Webinar for EPA Staff by Richard Kapuscinski Office of Land & Emergency Management (OLEM) October 2017 1 I. What is Vapor Intrusion and Why Does it Matter? A potential human exposure pathway -- a way that people may come into contact with hazardous vapors while performing their dayto-day indoor activities. Can occur in a broad range of land use settings (e.g., residential, commercial, institutional, industrial) Can arise from a broad range of hazardous substances, contaminants, and pollutants in the subsurface Can pose health or safety threats October 2017 U.S. Environmental Protection Agency 2 1
II. Briefing Organization & Scope Overview of EPA s vapor intrusion guidance OSWER VI Guide Purpose, scope, and development process Organization and summary of selected content and key recommendations October 2017 U.S. Environmental Protection Agency 3 II(A). Overview of EPA VI Guidance EPA s vapor intrusion guidance is comprised of two guides, published in June 2015, which supersede and replace EPA s 2002 draft guidance. Guide for petroleum releases from underground storage tanks sites. Guide for all other sites within EPA s jurisdiction. October 2017 U.S. Environmental Protection Agency 4 2
Technic lguidefor AddressingPetroleum V porintrusionat Le kingunderground Stor get nksites EPA 51 -R-15-1 June 2 15 This document is intended for use at any site subject to petroleum contamination from underground storage tanks where vapor intrusion may be of potential concern ( OUST PVI Guide ). It is applicable to both residential and non-residential settings (e.g., commercial and industrial). 5 OSWERTechnic lguide ForAssessingAnd Mitig tingthev por IntrusionP thw yfrom Subsurf cev porsources ToIndoorAir OSWER Publication 92.2-154 June 2 15 This document is intended for use at any site being evaluated pursuant to CERCLA or the corrective action provisions of RCRA, where vapor intrusion may be of potential concern ( OSWER VI Guide ). It is also intended for use by EPA s brownfield grantees, where vapor intrusion may be of potential concern. It is applicable to both residential and non-residential settings (e.g., commercial and industrial). 6 3
II(B1). Purpose of OSWER VI Guide Promote enhanced approaches and national consistency for addressing vapor intrusion at contaminated sites within EPA s jurisdiction { 1.3} 7 II(B2).Scope of OSWER VI Guide { 1.3} Not intended to alter existing requirements among OLEM s land cleanup programs; for example, about Development (e.g., evaluation of alternatives, cleanup levels), selection, and documentation of cleanup plans, or Periodic post-construction review to ensure protection of human health and the environment. 8 4
II(B2). Scope of OSWER VI Guide { 1.3} (continued) EPA recommends that tribal agencies and delegated state agencies consider this Technical Guide when implementing their respective programs for vapor intrusion assessment and mitigation. 9 II(B3). Highlights of Development Process for OSWER VI Guide Consensus-oriented, cross-epa process to prepare and vet the Guide (2012 to 2014) Public review draft available (mid-2013) Inter-agency review per Executive Order 12866 (September 2014 to June 2015) Numerous comments in docket (2002-2013), research publications, and guides from other entities considered also 10 5
Q&A : Purpose, Scope, Development 11 II(C1). OSWER VI Guide: Organization & Highlights of Content Executive summary identifies key recommendations A detailed description of the pathway { 2} Overview of the Guide { 3} Glossary identifies key terms 12 6
II(C1). OSWER VI Guide: Organization & Highlights of Content (continued) Offers information and recommendations about VI during each phase in the life cycle of a contaminated site that is subject to a federal cleanup statute Preliminary analysis & initial site assessment { 5} Site-specific investigation { 6} Response actions; e.g., building mitigation, remediation, institutional controls, etc. { 8} 13 II(C1). OSWER VI Guide: Organization & Highlights of Content (continued) Complements existing guidance and practices by offering supplemental information and recommendations about several Agency roles and responsibilities Summary of regulatory authorities { 1.2} Risk assessment & risk management { 7} Risk communication & community involvement { 9} 14 7
II(C2). Definitions & Glossary Vapor-forming chemical A volatile chemical that EPA recommends be routinely evaluated during a site-specific vapor intrusion assessment, when it is present as a subsurface contaminant. 15 II(C2). Definitions & Glossary (continued) Exposure pathway entails five elements Subsurface source of vapor-forming chemical(s) Vapor migration route(s) into and through the vadose zone Susceptibility of building to gas entry Vapor presence in building Exposure to occupants 16 8
II(C2). Definitions & Glossary (continued) Background refers to a vapor-forming chemical(s) or location(s) that is(are) not influenced by the releases from a site Concentrations in ambient air are not considered background when influenced by site-related releases 17 II(C3a). OSWER VI Guide: Key Recommendation Site-specific conditions justifying a consideration of the vapor intrusion pathway Known or suspected presence of vapor-forming chemicals in the subsurface environment (e.g., in groundwater, soil, conduits or tunnels) Proximate presence (or reasonable expectation of same in the future) of a building that is or could be occupied by humans; or an unoccupied structure (e.g., explosion hazard) 18 9
October 2017 19 Image Source: EPA [2012], Figure 9 II(C3b). Key Recommendation: How near is near? { 6.2.1} Utilize 100 feet to define an initial lateral inclusion zone for vapor intrusion assessment for purposes of a preliminary analysis Otherwise, investigate and evaluate soil vapor migration distance (e.g., define inclusion zone(s) for assessing vapor intrusion in specific buildings) on a sitespecific basis 20 10
II(C3c). Highlights: EPA s Authorities to Address Non-residential Buildings The sources of EPA authority and requirements for addressing subsurface vapor intrusion are the relevant statutes and regulations { 1.2}, which include CERCLA as amended RCRA, as amended EPA s authority and responsibilities are distinct and different from those of OSHA. 21 II(C3d). Highlights: Considerations for Prioritizing Among Buildings { 6.2.2} Source strength and proximity; e.g., Some non-residential buildings may overlie sources in the vadose zone Building construction and operations; e.g., Continuously occupied buildings may warrant priority, all else being equal Vapor migration ease; e.g., Utility tunnels may facilitate vapor entry 22 11
Q&A : Key Recommendations About When & Where 23 II(C3e). Key Recommendations: Human Health Risk Assessment { 7.4} Generally conduct a human health risk assessment to determine whether the potential human health risk posed to building occupants is within (or exceeds) acceptable levels, consistent with applicable statutes and considering EPA guidance; for example, OSWER hierarchy of sources for toxicity values Risk Assessment Guidance for Superfund, Part F 24 12
II(C3f). Key Recommendations: Risk Management EPA recommends that OSWER programs make the risk management determination to take response action(s) consistent with their statutes and regulations and considering existing program guidance { 7.4.1}. Consider reasonably expected future conditions, in addition to current conditions { 3.2 and 7.4.1} 25 II(C3f). Key Recommendations: Risk Management (continued) Select, recommend, and document response action(s) and cleanup plans consistent with statutes and regulations and considering existing program guidance { 7.7} 26 13
II(C3g). Key Recommendations: Community Involvement { 3.4, 6.2.3, 6.5.5, & 9} (continued) Develop and periodically refine a community involvement or public participation plan Implement this plan throughout project phases Assessment, including planning and risk communication Response actions (e.g., remediation; mitigation; associated monitoring and institutional controls) 27 Q&A : Risk Assessment, Communication & Management 28 14
Guidance About VI Found On-line https://www.epa.gov/vaporintrusion OSWER Technical Guide For Assessing And Mitigating The Vapor Intrusion Pathway From Subsurface Vapor Sources To Indoor Air Technical Guide For Addressing Petroleum Vapor Intrusion At Leaking Underground Storage Tank Sites October 2017 U.S. Environmental Protection Agency 29 Guidance About VI Found On-line (continued) https://www.epa.gov/vaporintrusion/vaporintrusion-superfund-sites Compilation of Information Relating to Early/Interim Actions at Superfund Sites and the TCE IRIS Assessment Assessing Protectiveness at Sites for Vapor Intrusion October 2017 U.S. Environmental Protection Agency 30 15
Additional Introductory Presentations Site-specific investigations of vapor intrusion (October 31) Cleanup plans for vapor intrusion (November 2) October 2017 U.S. Environmental Protection Agency 31 Contact Information for Speaker Rich Kapuscinski Kapuscinski.rich@epa.gov (703) 305-7411 October 2017 U.S. Environmental Protection Agency 32 16