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Point Sources of Emerging Contaminants Along the Colorado River Basin: Impact on Water Use and Reuse in the Arid Southwest
Citation:
Jones-Lepp, T., C. Sanchez, D. Alvarez, D. Wilson, AND R. Taniguchi-Fu. Point Sources of Emerging Contaminants Along the Colorado River Basin: Impact on Water Use and Reuse in the Arid Southwest. D. Barcelo (ed.), SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, Netherlands, 430:237-245, (2012).
Impact/Purpose:
Located in the western half of the United States (US) is the Colorado River is a major source of water (e.g., drinking, agricultural, industrial) for millions of people living in the southwestern part of the United States (e.g., Arizona, Southern California, Colorado, Nevada, and Utah) and Baja California, Mexico. The focus of this paper was to identify and characterize point sources of a select subset of emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs) entering the Colorado River using advanced sampling, extraction, analytical methods/techniques. Samples were collected throughout the Colorado River Basin (CRB), starting in the Upper Basin at Grand Lake, Colorado (the headwaters of the Colorado River), down the Lower Basin, and concluding at the Northern International Boundary (NIB) between California and Mexico.
Description:
Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf of California. At selected locations in the Colorado River Basin (sites in Colorado, Utah, Nevada, Arizona, and California), waste stream tributaries and receiving surface waters were sampled using either grab sampling or polar organic chemical integrative samplers (POCIS). The grab samples were extracted using solid-phase cartridge extraction (SPE), and the POCIS sorbents were transferred into glass gravity-flow chromatography columns and eluted with solvents. All extracts were prepared for, and analyzed by, liquid chromatography-electrospray-ion trap mass spectrometry (LC-ESI-ITMS). Log DOW values were calculated for all ECs in the study and compared to the empirical data collected. POCIS extracts were screened for the presence of estrogenic chemicals using the Yeast Estrogen Screen (YES) assay. Extracts from the 2008 POCIS deployment in the Las Vegas Wash showed the second highest estrogenicit response. In the grab samples, the antibiotic azithromycin was detected in all but one urban wastestream, with concentrations ranging from 30 ng/L to 2790 ng/L. Other ECs were detected in these urban waste streams at concentrations ranging from low ppt, 10 ng/L to 500 ng/L, to ppb levels, 3000 ng/L for pseudoephedrine. Those ECs that were detected in the main surface water channels (those that are diverted for urban use and irrigation along the Colorado River) were in the region of the limit-of-detection (e.g., 10 ng/L), but most were below detection limits.