Analysis of Escherichia coli, total recoverable iron, and dissolved selenium concentrations and loads for selected 303(d) listed segments in the Grand Valley, western Colorado, 1980–2018 (ver. 3.0, August 2021)

The U.S. Geological Survey (USGS), in cooperation with the Grand Valley Drainage District and the Colorado Water Conservation Board, conducted a loading analysis for selected constituents and tributaries to the Colorado River in the Grand Valley, western Colorado, using data from 1991 to 2018, to characterize concentrations, stream loading, and load reductions for Escherichia coli, total recoverable iron, and dissolved selenium for stream segments on the State of Colorado 303(d) list of impaired waters. Escherichia coli, total recoverable iron, and dissolved selenium concentrations and streamflow data were compiled from the Water Quality Portal (WQP). The data were submitted to the WQP by the USGS, Colorado Department of Public Health [...]