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Emerging Contaminants in US Drinking Water: Do you know where your water's been?
GLASSMEYER, S., E. Furlong, D. Kolpin, R. J. MILTNER, AND S. Werner. Emerging Contaminants in US Drinking Water: Do you know where your water's been? Presented at Society of Environmental Toxicology and Chemistry Ohio Valley Chapter Annual Meeting, Bloomington, IN, October 03, 2008.
To be presented at the Society of Environmental Toxicology and Chemistry, Ohio Valley Chapter Annual Meeting
The drinking water and wastewater cycles are integrally linked. Chemicals that are present in household wastewater may be sufficiently mobile and persistent to survive on-site or municipal wastewater treatment and post-discharge environmental processes. Such compounds have the potential to reach surface and ground waters. These downstream / down gradient waters are typically the source for another community’s drinking water. To determine which wastewater chemicals persist through drinking water treatment, a joint USEPA / USGS study examined source and finished waters for nine drinking water treatment plants from across the United States known to be impacted by wastewater. All water samples were analyzed for 96 different emerging contaminants, including 35 pharmaceuticals, at sub-ug/L levels. The sample collection was designed to account for residence time within the plant in order to match waters before and after treatment. The investigated utilities used varying source waters (surface or ground water), disinfectants (chlorine, chlorine dioxide, chloramine, ozone or UV), and produced different volumes of treated water per day (2.3 to 200 mgd). Thirty-nine chemicals were detected at least once, with 32 chemicals detected in the source waters and 26 chemicals detected in the finished waters. Overall, the most frequently detected chemicals were aspirin (60 %), bupropion (60 %), caffeine (40 %), carbamazepine (40 %), tri(2-chloroethyl) phosphate (40 %) and venlafaxine (40 %). The greatest number of chemicals detected in a single source water sample was 15; the greatest number detected in a single finished water was 11. In general, the results from locations that used conventional treatment (coagulation, clarification, filtration, and chlorination) showed negligible removal of the monitored emerging contaminants. The results from those sites that used more advanced treatment (granular activated carbon adsorption, ozonation or UV irradiation) showed greater removal percentages.