Probabilistic analysis of risks to U.S. drinking water intakes from 1,4‐dioxane in domestic wastewater treatment plant effluents
The risks of 1,4‐dioxane (dioxane) concentrations in wastewater treatment plant (WWTP) effluents, receiving primarily domestic wastewater, to downstream drinking water intakes was estimated using distributions of measured dioxane concentrations in effluents from 40 WWTPs and surface water dilution factors of 1,323 drinking water intakes across the U.S. Effluent samples were spiked with an d8‐1,4‐dioxane internal standard in the field immediately after sample collection. Dioxane was extracted with ENVI‐CARB‐Plus solid phase columns and analyzed by GC/MS/MS, with a limit of quantification of 0.30 µg/L. Measured dioxane concentrations in domestic wastewater effluents ranged from <0.30 to 3.30 µg/L, with a mean concentration of 1.11 ± 0.60 µg/L. Dilution of upstream inputs of effluent were estimated for U.S. drinking water intakes using the iSTREEM model at mean flow conditions, assuming no in‐stream loss of dioxane. Dilution factors ranged from 2.6 to 48,113, with a mean of 875. The distributions of dilution factors and dioxane concentration in effluent were then combined using Monte Carlo analysis to estimate dioxane concentrations at drinking water intakes. This analysis showed the probability was negligible (p = 0.0031) that dioxane inputs from upstream WWTPs could result in intake concentrations exceeding the USEPA's drinking water advisory concentration of 0.35 µg/L, prior to any treatment of the water for drinking use. Integr Environ Assess Manag © 2013 SETAC
Customer comments
No comments were found for Probabilistic analysis of risks to U.S. drinking water intakes from 1,4‐dioxane in domestic wastewater treatment plant effluents. Be the first to comment!