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Development of Soil Gas Sampling Methods for PFAS Compounds
Citation:
Lutes, C., R. Truesdale, C. Holton, H. Hayes, J. Zimmerman, A. Williams, AND B. Schumacher. Development of Soil Gas Sampling Methods for PFAS Compounds. Air & Waste Management Association conference Advancements in Vapor Intrusion and Emerging Contaminant Air Quality Issues, Virtual, September 23 - 24, 2021.
Impact/Purpose:
The research will provide regulators information that will help them (1) decide whether VI should be evaluated at the hundreds of sites where PFAS are reasonably expected to have been released to the subsurface and (2) determine what additional research is needed to evaluate any such threat further before making such policy determinations.
Description:
At least four polyfluorinated organic substances (i.e., 4:2-, 6:2-, 8:2- and 10:2- fluorotelomer alcohols; FTOHs) have sufficient vapor pressure to be designated as “vapor-forming chemicals.” In accordance with the OSWER Technical Guide For Assessing And Mitigating The Vapor Intrusion Pathway From Subsurface Vapor Sources To Indoor Air (“OSWER VI Guide”, US EPA 2015a), “’Vapor-forming chemicals’ warrant investigation for vapor intrusion when they occur as subsurface contaminants at sites subject to a federal statute for land cleanup (e.g., CERCLA, RCRA corrective action).” This investigation represents the U.S. Environmental Protection Agency’s (EPA’s) initial research into whether the VI exposure pathway is pertinent to PFAS chemicals, with a focus on FTOHs, which are common chemical intermediaries and byproducts in some PFAS manufacturing operations. FTOHs are also present in many consumer and building products and have been measured in ambient air and surface water (e.g., Yamazaki et al., 2021). This initial investigation has been designed to determine whether there is sufficient attenuation (e.g., due to biodegradation) of PFAS vapor concentrations, if any, in the vadose zone overlying PFAS-contaminated groundwater or soil to limit or prevent PFAS VI. Several potential sites have been identified and site access is being sought. If site access, sampling and analysis occur this summer, preliminary results will be presented at the conference once cleared and approved by EPA. If data is not available then the presentation will be of progress of the project, lessons learned and future directions.
