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Wastewater to Drinking Water: Are Emerging Contaminants Making it Through?
Citation:
Alvarez, D. AND T. L. JONES-LEPP. Wastewater to Drinking Water: Are Emerging Contaminants Making it Through? Presented at Lake Mead Science Symposium, Las Vegas, NV, January 13 - 14, 2009.
Impact/Purpose:
Presentation
Description:
Lake Mead serves as the primary drinking water source for Las Vegas, Nevada and surrounding communities. Besides snow-melt from the Rockies water levels in the lake are supplemented by the inflow of treated wastewater from communities along the Colorado River, including Las Vegas. This use-reuse practice is becoming commonplace in the arid Southwest and begs the question “Are organic contaminants, originating in the wastewater, ending up in the drinking water?” In 2005, a study was conducted using time-weighted passive sampling devices to track the occurrence of trace amounts of pharmaceuticals and personal care products, pesticides, industrial chemicals, and chemicals characteristic of wastewater treatment plant (WWTP) effluents at two sites in Las Vegas Wash (LVW), one site near Hemingway Harbor in Lake Mead, and in finished drinking (tap) water within the City of Las Vegas. As predicted, the largest abundance and highest concentrations of targeted chemicals were present at the second site in LVW downstream of the confluence of three WWTP effluents. Two antibiotics, azithromycin and clindamycin, along with two illicit drugs, methamphetamine and Ecstasy, were measured in LVW along with numerous pesticides and chemicals indicative of WWTP effluents. Several pesticides were detected above background levels in the drinking water sample at concentrations of 10 to 97 pg/L. Data from the yeast estrogen screen (YES) correlated with the chemical measurements as the highest estrogenic potential was measured in samples from the LVW. Hemingway Harbor and the drinking water samples did not have a measurable estrogenicity above background levels.