Geochemical and Hydrologic Factors Controlling Subsurface Transport of Poly- and Perfluoroalkyl Substances, Cape Cod, Massachusetts

Abstract

Growing evidence that certain poly- and perfluoroalkyl substances (PFASs) are associated with negative human health effects prompted the U.S. Environmental Protection Agency to issue lifetime drinking water health advisories for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in 2016. Given that groundwater is a major source of drinking water, the main objective of this work was to investigate geochemical and hydrological processes governing the subsurface transport of PFASs at a former fire training area (FTA) on Cape Cod, Massachusetts, where PFAS-containing aqueous film-forming foams were used historically. A total of 148 groundwater samples and 4 sediment cores were collected along a 1200-m-long downgradient transect originating near the FTA and analyzed for PFAS content. The results indicate that unsaturated zones at the FTA and at hydraulically downgradient former domestic wastewater effluent infiltration beds both act as continuous PFAS sources to the groundwater despite 18 and 20 years of inactivity, respectively. Historically different PFAS sources are evident from contrasting PFAS composition near the water table below the FTA and wastewater-infiltration beds. Results from total oxidizable precursor assays conducted using groundwater samples collected throughout the plume suggest that some perfluoroalkyl acid precursors at this site are transporting with perfluoroalkyl acids.

Hillslope groundwater discharges provide localized stream ecosystem buffers from regional per‐ and polyfluoroalkyl substances contamination

“…Room‐temperature samples were sonicated briefly and shaken before a 20‐ml aliquot was added to a 50‐ml polypropylene centrifuge tube. Then, 40 μl of a 0.03‐ng/μl internal standard solution was added to each centrifuge tube before samples were subjected to solid phase extraction involving 0.1% ammonium hydroxide in methanol, methanol, and deionized water, similar to published methods (Houtz, Sutton, Park, & Sedlak, 2016; Taniyasu et al, 2008; Weber, Barber, LeBlanc, Sunderland, & Vecitis, 2017). PFAS standards were obtained from Wellington Laboratories in Ontario, Canada (PFAC‐24PAR and MPFAC‐24ES).…”

“…Liquid chromatograph–tandem mass spectrometer (LC–MS/MS) analysis that has been previously documented (e.g., Dassuncao et al, 2019; Weber et al, 2017) was used with slight modifications for this data set as described below. Analysis was completed using an Agilent 6460 triple quadrupole LC–MS/MS with an electrospray ionization source.…”

Organic micropollutants in groundwater of India—A review

“…With good porosity and hydraulic conductivity, sandy, loamy, and silty textures result in faster movement of micropollutants into groundwater (Gupta, Gupta, Chauhan, Singh, & Singh, ; Jayshree & Vasudevan, ; Mishra & Sharma, ; Mutiyar et al, ), whereas clay layers, due to poor permeability, result in the slow movement of micropollutants into groundwater (Ghose et al, ). The presence of PFAS in groundwater depends on the characteristics of the sediments and hydro‐chemical properties of PFAS (Weber, Barber, LeBlanc, Sunderland, & Vecitis, ).…”

Occurrence and behavior of per‐ and polyfluoroalkyl substances from aqueous film‐forming foam in groundwater systems

“…A study of a groundwater plume located on Cape Cod, MA, found evidence of migration of precursors and conversion to PFCAs and PFSAs as the plume migrated downgradient (Weber, Barber, LeBlanc, Sunderland, & Vecitis, ). The study also found that there were two active source areas, an FTA and a domestic sewage sludge drying bed, that continued to contribute to PFCAs, PFSAs, and precursors two decades after use of the facilities ceased, demonstrating both the mobility of precursors and the longevity of PFAS source zones (Weber et al., ).…”