FACTORS INFLUENCING PFAS OCCURRENCE IN DOMESTIC WELLS WITHIN AN UNCONVENTIONAL OIL AND GAS PRODUCING REGION OF NORTHERN WEST VIRGINIA

Per-and polyfluorinated substances (PFAS) have become the focus of increasing public and regulatory scrutiny because of their environmental persistence and capacity to produce negative health impacts even at low concentrations (parts per trillion). Recent public disclosures have uncovered the use of PFAS compounds and their precursors in hydraulic fracturing and other drilling fluids in at least a thousand oil and gas wells across eight states in the United States, raising alarm about the use of PFAS in the oil and gas industry overall. The potential presence of PFAS compounds in produced waters and other oil and gas waste streams presents a challenge for the safe re-use and management of oil and gas wastes, as well as a possible vector for drinking water contamination. Little data describing the prevalence of PFAS compounds in water resources within oil and gas producing regions in the United States exists and thus the overall environmental impact of PFAS use in the oil and gas industry is largely undetermined. We present results from targeted and non-targeted analyses of PFAS compounds present in 48 domestic drinking water wells and 8 surface water bodies located within a dense oil and gas producing region of northern West Virginia. Through the joint investigation of inorganic (major cations and anions, metals, and trace elements) and organic (DRO, GRO, VOCs) water quality parameters and geospatial trends, we evaluate the major hydrologic and anthropogenic factors influencing the occurrence of PFAS in domestic groundwater sources. Our results reveal 67% (n=30) of domestic water wells within the study region contain detectable levels of at least one PFAS compound and that PFOA (49%, n=23), NaDONA (33%, n=16), PFBA (24%, n=11) represent the most frequently detected compounds. Elevated PFAS concentrations were associated with topographic highs and calcium dominated water types typical of recent recharge in the area, suggesting younger groundwater is more susceptible to PFAS contamination. Proximity to industrial discharge permits, including those primarily used by the oil and gas industry, were associated with both PFAS concentrations and the number of compounds detected. This study presents an initial look at PFAS occurrence in water resources in an area dominated by oil and gas development and a guide for future work.