Sucralose and Predicted De Facto Wastewater Reuse Levels Correlate with PFAS Levels in Surface Waters

Per- and polyfluoroalkyl substances (PFAS) pose risks to human health and ecosystems and are commonly found in wastewater treatment plant (WWTP) effluents discharged into surface waters. WWTPs continuously discharging PFAS into surface waters are hypothesized to lead to pervasive PFAS for downstream drinking water treatment plant (DWTP) intakes. To investigate the impact of this unplanned (de facto) wastewater reuse, we analyzed river water and WWTP effluent samples for 19 target PFAS and a surrogate chemical (sucralose) in a large watershed, with >165 WWTP discharges and multiple DWTP surface water intakes. The ∑PFAS concentrations of WWTP effluents (50–200 ng/L) were higher than that of the river water, with the same relative distributions of individual PFAS found in both samples. Surface water samples showed a direct and linear relationship between ∑PFAS and sucralose concentrations [∑PFAS (ng/L) = 0.0014 × (sucralose (ng/L)) + 19; R2 = 0.92] or predicted de facto reuse levels. Unplanned wastewater reuse could be a widespread source of PFAS for thousands of DWTPs. This study provides valuable guidance for future initiatives aimed at identifying sources of PFAS through de facto reuse modeling and chemical surrogate sampling.