Characterization of the Potential Long-Term Impact from Sedimentary PFAS at a Historically Contaminated Textile Waste Site

Per- and polyfluoroalkyl substances (PFAS) are pervasive pollutants at historically contaminated sites throughout the United States and beyond. Two such sites in Rhode Island, USA, are textile-mill-associated waste retention ponds known to introduce PFAS contamination to the adjacent river, estuary, and eventually the Atlantic Ocean. Here, we thoroughly investigated the retention ponds as a long-term source of PFAS via water passive sampling, sediment coring, and laboratory-derived partitioning coefficients, Kd, with field sediment and water. Additional studies were performed to assess the mobility and estimate the mass fluxes of PFAS from sediment to water. Retention pond 1 was more contaminated (up to 26 ng/L PFOA in water and 74 ng/g PFTrDA in sediment). Derived log Kd values ranged from 1 to 5 for most PFAS, indicating a shift from relative mobility to high storage potential in sediment. Estimated loss fluxes from the sediment varied between 5 and 228 μg m–2 year–1, resulting in desorption times from 3 years for FPeSA to >100 years for FOSA. The combined evidence suggests that this textile mill retention pond, if left untreated, constitutes a source of long-term contamination to the river.