The impact of two fluoropolymer manufacturing facilities on downstream contamination of a river and drinking water resources with per- and polyfluoroalkyl substances

Abstract

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are emerging contaminants that have been detected in the environment, biota, and humans. Drinking water is a route of exposure for populations consuming water contaminated by PFAS discharges. This research study reports environmental measurement concentrations, mass flows, and the fate of dozens of PFASs in a river receiving effluents from two fluoropolymer manufacturing facilities. In addition to quantified levels of PFASs using LC-and GC-MS analytical methods, the total amount of unidentified PFASs and precursors was assessed using two complementary analytical methods, absorbable organic fluorine (AOF) determination and oxidative conversion of perfluoroalkyl carboxylic acid (PFCA) precursors. Several dozen samples were collected in the river (water and sediment) during four sampling campaigns. In addition, samples were collected in two well fields and from the outlet of the drinking water treatment plants after chlorination. We estimated that 4295 kg PFHxA, 1487 kg 6:2FTSA, 965 kg PFNA, 307 kg PFUnDA, and 14 kg PFOA were discharged in the river by the two facilities in 2013. High concentrations (up to 176 ng/g dw) of odd long-chain PFASs (PFUnDA and PFTrDA) were found in sediment samples. PFASs were detected in all 15 wells, with concentrations varying based on the location of the well in the field. Additionally, the presence of previously discharged PFASs was still measurable. Significant discrepancies between PFAS concentration profiles in the wells and in the river suggest an accumulation and transformation of PFCA precursors in the aquifer. Chlorination had no removal efficiency and no unidentified PFASs were detected in the treated water with either complementary analytical method. Although the total PFAS concentrations were high in the treated water, ranging from 86 to 169 ng/L, they did not exceed the currently available guideline values.

Evaluation of a national data set for insights into sources, composition, and concentrations of per- and polyfluoroalkyl substances (PFASs) in U.S. drinking water

“…As mentioned, PFAS co-occurrence may reflect release from multiple PFAS-containing products or applications, changes in PFAS use over time, and/or precursor transformation. PFAS mixtures are therefore consistent with complex use, release, and chemistry, as well as previous studies where multiple PFASs were measured in surface water and groundwater at PFAS-impacted sites such as military installations, landfills, and PFAS or fluoropolymer manufacturing facilities (Anderson et al 2016; Bach et al 2017; Houtz et al 2013; McGuire et al 2014; Oliaei, F. et al 2006; Oliaei et al. 2013; Weber et al 2017).…”

“…PFOA was the primary PFAS historically used for manufacturing some types of polytetrafluoroethylene (Prevedouros et al 2006). So not surprisingly, aqueous data from previous studies of sites impacted by historical fluoropolymer manufacturing practices exhibit ratios reflective of high PFOA concentrations relative to other PFASs (Bach et al 2017; Dauchy et al 2012; Oliaei et al 2013). PFAS ratios in WWTP effluent data also reflect elevated levels of PFOA (Ahrens et al 2009).…”

“…Use of odds ratios to further elucidate release type is limited because multiple sources may explain co-occurrence of a single pair. For example, PFOS and PFHxS are documented to co-occur at sites impacted by AFFF, fluoropolymer manufacturing, and landfills (Bach et al 2017; Dauchy et al 2012; McGuire et al 2014; NHDES 2017; Oliaei et al 2013).…”

“…The highest odds ratio was observed for PFOS and PFHxS and this pair also exhibited a significant, positive correlation in concentrations (Figure S.2). PFOS and PFHxS were both major components of historic AFFF formulations and are commonly reported to occur at AFFF-impacted sites (Anderson et al 2016; Houtz et al 2013; Hull et al 2017; McGuire et al 2014); however, they are also documented to co-occur at sites impacted by manufacturing activity (Bach et al 2017; Dauchy et al 2012; Oliaei et al. 2013) and in WWTP effluent (Ahrens et al 2009).…”

“…the majority of surface water samples with detections contained PFCAs but not PFSAs). As discussed, environmental samples with higher percentages of PFCAs have been attributed to sources including fluoropolymer manufacturing, landfills, and WWTP effluent (Ahrens et al 2009; Arvaniti and Stasinakis 2015; Bach et al 2017; Dauchy et al 2012; Houtz et al 2016; Oliaei et al 2013; Weber et al 2017), which all have relevance to surface water scenarios. Manufacturing facilities may impact surface water through surface runoff, storm water outfalls, or industrial WWTP effluent.…”