AARST_Radon_Reporter_July_2022

22 | July 2022 VAPOR INTRUSION As the regulatory scrutiny intensified on the VI pathway, the EPA updated its toxicological review for one of the most ubiquitous chlorinated solvents, Trichloroethylene or TCE, in our nation’s groundwater. Published in 2011, this review suggested that a low level of TCE may pose an immediate potential hazard and adverse developmental outcomes could potentially result from short-term TCE inhalation exposures during pregnancy. One of the more controversial studies that the EPA used identified that even a woman’s single exposure to TCE during fetal development may be sufficient to produce an adverse developmental effect. The VI pathway was quickly designated a primary conduit for TCE vapors to enter a structure and amplified this potential risk. As a consequence of evolving VI guidance and developmental toxicity concerns with TCE exposure, many states, including New York, Michigan, Minnesota, and Massachusetts, systemically started to reevaluate and, where appropriate, reopen closed sites with TCE contamination. Maintaining regulatory closure So, given the rapidly changing regulatory climate, how can a responsible party secure and, perhaps more importantly, maintain regulatory closure for a contaminated site? A phase-based approach may be the best choice, coupled with some new tools. Phase 1. The first phase should focus on an internal audit of your portfolio of active and/or closed sites. There are ways to help ensure that the audit is privileged and confidential. This audit should be conducted through legal counsel and include an experienced consulting expert to help evaluate the risk-based assumptions and evaluate any new pathways (like VI). This expert should consider, among other criteria, the applicable screening levels for the VI pathway and conduct an updated receptor survey for both on and off-site land uses. Phase 2. The second phase could involve collecting additional samples. If it is determined that the VI pathway was not adequately assessed or evaluated, then you should consider developing a VI Decision Matrix, VI Sampling and Analysis Plan, and updating the VI Conceptual Model. Phase 3. The third phase is site-specific and data-driven. Developing a so-called Long Term Stewardship (LTS) Plan that embraces and effectively uses new regulatory, legal, and technical tools to manage the VI pathway is considered a best practice. There is state and federal guidance available to draft a successful LTS Plan or equivalent approach. There are important legal mechanisms, including environmental restrictive covenants or ordinances, which when properly drafted can be very effective to manage potential future VI pathway liability. An LTS Plan can include new technology and tools, like the newly patented remote monitoring device known as the Vapor Sentinel. This new device provides remote telemetric monitoring technology to provide around-the-clock data collection and reporting. The VI pathway can be complex and the science continues to evolve at a rapid pace, but with counsel from legal and environmental professionals and a phase-based plan tailored to your site, you can successfully secure and maintain closure. The last article in this series will cover various landowner liability protections and some recent toxic tort litigation centered on the VI pathway and alleged TCE exposure. This publication should not be construed as legal advice or legal opinion on any specific facts or circumstances. The contents are intended for general informational purposes only, and you are urged to consult your lawyer on any specific legal questions you may have concerning your situation. David R. Gillay, Esq., is a Partner in the Environmental Department of Barnes & Thornburg LLP’s Indianapolis Office and may be reached at 317.946.9267 or david.gillay@btlaw.com . 1 David leads Barnes & Thornburg LLP’s Environmental department's remediation, redevelopment, and environmental transactions prac- tices. He has focused on the legal, regulatory, and technical impact and implications related to the vapor intrusion pathway, chlorinated VOCs (with an emphasis on TCE), and potential long-term stewardship obligations related to environmentally challenged properties for nearly two decades. David is a frequent writer and speaker, having participated in a variety of private association, client, and continuing legal and business education seminars with a special focus on vapor intrusion, TCE, and developing cost-effective solutions to manage residual contamination as part of redevelopment projects and the sale of contaminated property. David was recently elected to join the American Association of Radon Scientists and Technologists (AARST) Board of Directors and continues to serve as counsel of record for the Midwestern States Environmental Consultants Association (MSECA). Prior to joining Barnes & Thornburg, he obtained an advanced environmental engineering degree and practiced as an environmental consultant on various projects across the country.