Industrial sources of per- and polyfluoroalkyl substances (PFAS) to a sewershed in Ontario, Canada

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment despite global regulatory action to restrict their use in industrial processes and products. The objective of this reconnaissance sampling was to understand current industrial use and ongoing sources of PFAS in Ontario. Fourteen PFAS were analyzed in effluents from four sectors: electroplaters, laundry and carpet cleaners, landfills, and circuit board manufacturers that discharge to sewersheds connected to wastewater treatment plants. Maximum concentrations were detected in carpet cleaning wastewater: 79,000 ng/L for perfluorohexane sulfonate (PFHxS), 26,000 ng/L perfluorooctane sulfate (PFOS), and 9400 ng/L perfluorooctanoic acid (PFOA). Total summed PFAS (∑PFAS₁₄) concentrations were highest in laundry and carpet cleaners > electroplaters > landfill leachate > circuit boarders. These results indicate that PFAS continue to be used in select manufacturing and processing facilities and that the elevated levels are associated with past and current uses in commercial products.