Summary of water-quality data for selected streams in Colorado

This report presents the first statewide summary of water-quality data for selected streams in Colorado. Included in the report are a tabulation of the 165 surface-water-sampling sites for which five or more analyses of major chemical constituents were available at the end of the 1978 water year and a tabulation of the types--major chemical constituents, trace or minor elements, biological constituents, pesticides, or radio-chemicals--and number of water-quality analyses available at each of the 165 sites. Also included are statistical summaries, including regression summaries showing the relation between specific conductance and major chemical constituents, for 117 sites for which 20 or more analyses of major chemical constituents are available. Examples of linear-regression plots of specific conductance and selected major chemical constituents based on data from the Eagle River at Gypsum, Colo., are presented. Decisions to modify the frequency of collection or the types of constituents determined at many sites are facilitated by the statistal summaries. (USGS)