Studies were done during 1983-84 to determine the effect of coal mining in Pleasant Valley and construction of State Road 264 in Eccles Canyon on the water quality of local streams and on Scofield Reservoir. Streamflow during 1983-84 set high-flow records in all gaged streams and transported considerable sediment and associated trace metals and nutrients to Scofield Reservoir. Concentrations of most toxic substances were not sufficient to constitute a hazard in the streams or reservoir; however, concentrations of total phosphorus in the streams commonly exceeded waterquality criterion for phosphate as phosphorus of 0.05 milligram per liter, established by the State as an indicator of pollution.
Data from Eccles Canyon creek, which is in an actively mined area, were compared to data from Boardinghouse Canyon creek, which is in a nearby canyon with no active mining or construction activities. Concentrations of iron, manganese, and zinc were substantially larger in Eccles Canyon creek than in Boardinghouse Canyon creek. Loads of suspended sediment during storms and base-flow conditions also were larger in Eccles Canyon creek.
Concentrations of ammonia nitrogen, total phosphorus, mercury, and zinc in water from Scofield Reservoir occasionally exceeded Utah State water-quality standards and criteria for protection of aquatic wildlife that were in effect during 1983-84. In combination with the generally cooler spring temperatures, shortened growing season, and greater flushing rate for the reservoir, the large inflow of water into the reservoir prevented the occurrence of blue-green blooms common in earlier years. Large concentrations of orthophosphorus and manganese were released from sediment cores, and concentrations of manganese in the hypolimnion frequently exceeded the Federal drinking-water standard.
|Title||Potential effects of coal mining and road construction on the water quality of Scofield Reservoir and its drainage area, central Utah, October 1982 to October 1984|
|Authors||Doyle W. Stephens, Kendall R. Thompson, James B. Wangsgard|
|Publication Subtype||USGS Numbered Series|
|Series Title||Water-Resources Investigations Report|
|Record Source||USGS Publications Warehouse|