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USEPA Office of Research and Development FY21 Update and Contaminants of Emerging Concern During De Facto Water Reuse
Citation:
Glassmeyer, S. USEPA Office of Research and Development FY21 Update and Contaminants of Emerging Concern During De Facto Water Reuse. WateReuse Texas Annual Reuse Conference, webinar, TX, October 26, 2020.
Impact/Purpose:
This presentation gives a high level overview of the structure of ORD post-reorganization. It also discusses de facto reuse and the persistence of chemicals from wastewater into drinking water treatment .
Description:
While some communities are exploring direct potable reuse, de facto reuse (DFR) is occurring in many locations across the United States (i.e. unintentional indirect potable reuse from drinking water intakes being downstream of wastewater treatment plant outfalls). DFR may increase the possibility of contaminants of emerging concern (CECs) being present in the source water, and potentially the corresponding treated drinking water. We investigated one watershed with a wastewater treatment plant (WWTP) upstream of a drinking water treatment plant (DWTP) intake. The DFR at the intake was estimated to be 2.6 % during mean stream flow. There were no tributaries between the WWTP outfall and the DWTP intake, allowing for an investigation of fate and transport of CECs without the need to account for additional dilution. Of the 236 chemicals monitored in the study, 140 were detected at least once in the effluent, and 49 were detected at least once in the treated drinking water. Across the three sampling rounds of the study (October 2014, April 2015, and August 2015), 72 chemicals were always detected in the effluent, while only 5 chemicals were always detected in the treated drinking water; four of those five were disinfection by products, and the fifth was sucralose. When the overall concentration patterns were examined, most of the organic chemicals were clearly introduced into the water system through the WWTP effluent. In contrast, inorganic chemicals showed a more mixed source, with some exhibiting a wastewater source while others maintained a nearly constant concentration up- and downstream of the WWTP outfall.