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The Universal Soil Loss Equation will be used to <br />calculate the soil loss from the reclaimed mine sites <br />and the natural conditions to determine if untreated <br />drainage from the reclaimed mine sites is contributing <br />suspended solids above natural conditions. <br />The following sediment volume calculation is prepared in <br />accordance with U. S. Department of Agriculture, Technical <br />Notes, Agronomy Note #50, dated January, 1977. <br />USING THE UNIVERSAL SOIL LOSS EQUATION <br />It is assumed that all variables used in the USLE, except the <br />C -factor, are constant relative to the pre -mining (natural) <br />and post -mining (reclaimed) conditions. Therefore vegetative <br />condition is the key variable in making a determination <br />that potential sediment yeild is less after mining than before <br />mining. The "C" factor for the USLE is calculated from Figure <br />7, from agronomy note #50 dated January 1977 as follows: <br />Figure 7 - "C" Factors for Permanent Pasture and Rangeland <br />RECLAIMED AREA <br />NO APPRECIABLE CANOPY <br />CANOPY PERCENT GROUND COVER <br />------ -------------------------------- <br />• 60_0 4 80.0 <br />--------------69_ <br />0.0 % G 0.042 0.028 0.013 <br />Reclaimed * * * * * * * 0.028 * * * * * <br />NATURAL - ADJACENT AREA <br />CANOPY <br />25.0 % <br />42.3 % <br />50.0 <br />• <br />APPRECIABLE BRUSH <br />PERCENT GROUND COVER <br />60.0-----67.4--------------80.0 <br />G 0.040 0.030 0.013 <br />Natural * * * * 0.029 * * * * * * * * * <br />G 0.038 0.029 0.013 <br />4-19ii <br />10-02-92 <br />