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Water-quality investigation, Eel River, California

January 1, 1976

This report summarizes selected water-quality data collected in the Eel River, Calif., during a reconnaissance study from November 1971 through January 1975. It also includes a summary of the major inorganic chemical data collected near Dos Rios, at South Fork, and at Scotia since the early 1950's. The recent reconnaissance involved data collection for nitrogen, phosphorus, total organic carbon, trace elements, and pesticide compounds in the river at Van Arsdale Dam, near Dos Rios, at Fort Seward, and at Scotia.

The number of samples collected during the special reconnaissance is somewhat limited, and therefore the data are only an estimate of conditions that presently exist at selected sites in the river. Results indicate that most of the constituents were low in concentration; although some variability was measured for some constituents. Sampling was designed so that samples collected at each site would represent a large range in discharge. Results indicate that discharge was not the singular factor controlling the concentration variance for most constituents. However, the concentrations of total ammonia, phosphorus, arsenic, chromium, copper, and zinc indicated a direct relation with discharge at some sites.

Statistical analysis indicates that the past sampling program has been adequate to estimate the major chemical constituents of the river. Specific conductance in the river near its headwaters ranges from 110 to 300 micromhos about 98 percent of the time; and at Scotia, near the mouth, the specific conductance ranges from 110 to 340 micromhos about 98 percent of the time.

Results of regression analyses indicate that between 83 and 88 percent of the variance in specific conductance can be explained by discharge.

Publication Year 1976
Title Water-quality investigation, Eel River, California
DOI 10.3133/wri765
Authors George A. Irwin
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Water-Resources Investigations Report
Series Number 76-5
Index ID wri765
Record Source USGS Publications Warehouse