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APERC Statement A Second USGS Study in Colorado Finds Levels of NP Are Less Than EPA's Proposed WQC February 28, 2005 Another US Geological Survey (USGS) environmental monitoring study has confirmed that levels of nonylphenol (NP) found in Colorado streams are below EPA's proposed Water Quality Criteria (WQC) for this compound. The study determined levels of NP along with 61 other organic wastewater compounds.1 As expected, concentrations of all compounds tended to be highest in urban streams compared with other site types. Alkylphenols are typically found at only trace levels (less than a part per billion) in the aquatic environment in the United States. The USGS study in Colorado adds to an already well-founded understanding that levels of NP in US surface waters are below EPA's proposed WQC and are being effectively managed in this country. 1 Sprague, L.A., and Battaglin, W.A. (2005, January). Wastewater Chemicals in Colorado's Streams and Ground Water. US Geological Survey Fact Sheet 2004-3127.                                                                                                                                                   Site Map   ·   Feedback/Contact Us   ·   Members Only

Last reviewed: June 26, 2003