Water-quality data were collected from streams in a six-county area to determine if the streams were polluted and, if so, to determine the sources of the pollution. Eighty-three stream sites were selected for sampling in Eagle, Grand, Jackson, Pitkin, Routt, and Summit Counties. Also included are data from 28 sites in Routt County collected for a U.S. Geological Survey cooperative study on the Yampa River basin. A summary of data collected prior to this study, results of current chemical and biological sampling, and needs for future water-quality monitoring are reported for each county.
The kinds of data collected were site specific depending upon land-use activities. Data collected at selected sites included temperature, pH, specific conductance, dissolved oxygen, and stream discharge. Chemical data collected included nutrients, inorganics, organics, and trace elements. Biological data collected included counts and species composition of total and fecal-coliform bacteria, fecal-streptococcus bacteria, benthic invertebrates, and phytoplankton. Most of the sites were sampled three times: in April-June 1976, August 1976, and January 1977.
The major water-quality problems at the 17 sites sampled in Eagle County are related to mining, recreation, and geology. The Eagle River and Cross Creek in the vicinity of Minturn have concentrations of trace elements that exceed water-quality standards. Gore Creek is influenced by winter recreational use and the water during the winter has total bacteria counts as great as 72,000 per 100 milliliters and concentrations of un-ionized ammonia greater than 0.02 milligrams per liter downstream from the sewage-treatment plant. Mineralized water in the downstream reaches of the Eagle River results from natural chemical processes. The water-quality problems in Grand County, especially on the Fraser River, are related to recreation and urban activities. Chemical and biological indications of water-quality degradation exist for the Fraser River downstream from Winter Park.
