Distribution and concentrations of selected organochlorine pesticides and PCB's in streambed sediment and whole-body fish in the Upper Colorado River Basin, 1995-96

As a part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program, hydrologic and water-quality assessment of the Upper Colorado River Basin (UCOL) study unit began in 1994. Prior to the design of the integrated studies of water quality in the basin, a retrospective investigation was conducted to determine the availability of historical water-quality data and the location of previous research that occurred in the UCOL. The findings indicated that minimal data had been collected regarding the occurrence and distribution of organochlorine pesticides and polychlorinated biphenyls (PCB's) in streambed sediment and whole-body fish in the UCOL study unit (Deacon and Stephens, 1996). Organochlorine pesticides and PCB's, all of which are organochlorine compounds, have been specifically targeted by standards and guidelines that exist to protect water quality for human and wildlife health. In 1995-96, a survey of selected organochlorine pesticides and PCB's was conducte