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• The Colorado Water Quality Commission has classified the White River and its tributaries in the area of <br />concern as B2 (suitable for all uses, except whole body contact). However, this classification and its <br />associated numerical standards are still in a state of flux. Thus, because of the lack of state water quality <br />standards, concentrations of trace metals and toxic elements were reviewed for anomalies based primarily <br />on draft guidelines published by the U.S. Environmental Protection Agency (1975). <br />Most constituent concentrations in the surtace waters of the area are well within the limitations established <br />by the U.S. Environmental Protection Agency 91975) for the indicated uses. In many instances, trace metal <br />concentrations were found to be consistently below the level of detection of routine laboratory techniques <br />(particularly cadmium, lead, mercury, nickel, and silver). <br />Exceptions to the rule of few exceedances of the draft limitations deal with ammonia and total phosphate. <br />Approximately 61 percent of the ammonia concentrations measured at the routine monitoring stations <br />naturally exceeded the suggested limit of 0.02 milligrams per liter, necessary for the maintenance of <br />freshwater aquatic life. Although the remaining ammonia concentrations were below the level of detection <br />of the laboratory methods, it has not been uncommon to find concentrations of 0.1 to 0.6 milligrams per liter <br />in the streams and ponds of the area. The presence of ammonia in the area is probably the result of <br />biological degradation of nitrogenous organic matter, including animal waste in the lease area watersheds <br />as well as the White River above the lease area tributaries and leaching of fertilizers from irrigated fields in <br />• the White River Basin (Hem, 1970) <br />Over 80 percent of the background total phosphate concentrations exceeded the proposed EPA limitation <br />of 0.10 milligrams per liter for flowing waters not directly discharging into lakes or impoundments. <br />Phosphate concentrations at the baseline monitoring stations in the area have ranged from 0.04 to 1.81 <br />milligrams per liter, with the highest concentrations occurring during the snowmelt season in Red Wash. <br />The average total phosphate concentration of all samples collected during the inventory period was 0.40 <br />milligrams per liter. A portion of the phosphates may result from the degradation of animal wastes and <br />fertilizers in the area and upstream (Hem, 1970). the general relation between total phosphate and <br />suspended sediment concentrations, however, indicates that most of the phosphates have been carried <br />into the streams on sediment and have as their source the phosphorous content of the soils (McElroy et al, <br />1976). <br />II.C.2.d Sediment Yield An estimate of the average annual sediment yield to be expected from the lease <br />and adjacent areas was made using a methodology developed by the Pacific Southwest Inter-Agency <br />Committee (1968). Table II.C-7 contains the parameter and sediment yield estimates of the method. The <br />estimated average annual yield of 0.60 acre-foot per square mile from Figure II.C-22 compares favorably <br />with estimates made by the Colorado Land Use Commission (1974). Based on guidelines given by Strand <br />(1975) for streams with sand and clay bottoms and flow events resulting in high suspended sediment <br />concentrations, it is estimated that approximately 10 percent of the sediment yielded from the lease and <br />Permit Renewal #3 (Rev. 8/99) II.C~3 <br />