Study Quantifies Tap-Water Chemicals

Chemical oxidation processes used at drinking-water treatment plants, either ozonation or chlorination, argely control the occurrence of pharmaceutical and endocrine-disrupting compounds in the plant's finished water, according to the first peer-reviewed study of these compounds in treated U.S. tap water (Environ. Sci. Technol., DOI: 10.1021/es801845a). Previous studies have detected compounds such as naproxen and atrazine in treated wastewater, rivers, and reservoirs, but few data are available for these chemicals in treated U.S. drinking water. Researchers at the Southern Nevada Water Authority analyzed source water, finished drinking water, and distributed tap water from 19 utilities serving 28 million people for 51 potentially troublesome compounds during 2006 and 2007. They found significantly fewer of the compounds in tap water than in source or finished water. Team leader Shane A. Snyder says additional wastewater treatment would likely be the most prudent way to further reduce the compounds in tap water.