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States" dated July 1977, and soils data taken from a soils survey of the area done by the SCS and dated July 11, 1978. The various factors in the USLE are discussed below: The USLE is A = (R)(K)(LS)(C)(P) where: A =Sediment volume in tons per acre per year R =Rainfall factor K =Soil erodibility factor LS =Length-slope factor C =Crop management factor P =Control practice factor The rainfall factor (R) used for the Deserado Mine was 30 which was obtained from Figure 1 EPA-908, "Average Annual Value of Factor R." The soil erodibility factor (K) was taken from the SCS area soils survey. Where K factors were not available, a suitable value was obtained by using the material characteristics and using Figure 3, EPA-908, "Nomograph for Determining Soil Erodibility -Factor "K" or from Appendix A Factors "K" and'T". EPA-908. The length-slope factor (LS) was determined by measuring sub-area lengths and slope percentages on a map of the drainage basins. The lengths and slopes were then used to obtain the (LS) factors from Table 1 in EPA-908, "Values of the Topographic Factor'LS"'. The crop management factor (C) and the control practice factor (P) were assigned the value of 1.0 for disturbed areas. This value corresponds to freshly denuded sites with no conservation practices. Undisturbed areas were assigned values for (C) and (P) in accordance with their existing vegetative cover from Table 4, EPA-908, "'C" Factors for Permanent Pasture and Rangeland" and Table 6, EPA-908, "Determining Factor'P"." The percentages of vegetative cover were taken from Section II-F, Vegetation Report. Multiplying the factors R, K, LS, C and P yield the annual sediment yield A in tons per acre. Multiplying A by the acres in the subarea (Ar} yields the annual sediment yield in tons. A bulk density of 80 pounds per cubic foot was assumed for the settled solids. The estimated bulk density was based on the formula d = We Pc + Wm Pm + Ws Ps where: (Permit Renewal #3, 8/99j V-10