Julia Roth is an Environmental Engineer at Jacobs (formerly CH2M Hill). She specializes in emerging contaminants and vapor intrusion, with a primary focus on PFAS volatility, emissions, and atmospheric transport. She holds a degree in Biological Systems Engineering from Virginia Polytechnic Institute and State University.”
Are Per- and Polyfluoroalkl Substances (PFAS) a Vapor Intrusion Concern?
Research studies, as well as site investigations, over the past several years have provided a glimpse at the extent of PFAS contamination in the environment but have largely overlooked vapor-phase transport. The primary focus of these studies has been evaluating groundwater contamination and impacts to drinking water supplies. As more is learned about the transport of PFAS in groundwater systems, as well as the unique physical and chemical properties of these chemicals, it has become clear that other transport pathways need to be evaluated. Currently, little is known about the volatility and vapor-phase transport of PFAS in the subsurface and whether they pose a vapor intrusion (VI) concern. This review will provide a comparison of the physical and chemical properties of various PFAS compounds, with a focus on those found in indoor and outdoor air. This review will also discuss site and remedial scenarios where vapor-phase transport may be significant.
Comparative Adsorption: Considering Multiple Adsorbents for More than just PFOA and PFOS
With regard to PFAS treatment, individual States are developing screening values or promulgated drinking water values that are lower than the EPA Lifetime Health Advisory (LHA) values for PFOA and PFOS and/or more inclusive of other PFAS. Moreover, the EPA recently stated that LHAs are expected to be developed for PFBS and GenX this year, demonstrating the rapidly evolving regulatory landscape of PFAS. Limited data exist for comparative adsorption performance for a larger number of PFAS compounds. This presentation provides new pilot operating data treating ground water using four side-by-side adsorbents: GAC, ion exchange (IX), and two novel adsorbents not previously evaluated in field applications. One novel adsorbent is a bio-material developed outside the US, which is optimized for PFAS adsorption; the other is a surface-modified GAC studied under recent SERDP project. Comparative performance and projected life cycle costs will be discussed considering a larger number of 537.1 PFAS compounds.