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SOIL LOSS COMPARISON - RED CANYON MINE SITE <br />• RECLAIMED VERSUS NATURAL CONDITIONS <br />The following calculations are presented to determine if <br />untreated drainage from the reclaimed Red Canyon Mine <br />Site is contributing additional suspended solids <br />above natural conditions. <br />Natural conditions are considered to be those conditions <br />that existed during the August 1983 vegetation study. <br />The 1983 vegetation report is contained in the permit <br />Exhibit F. The results of this vegetation report are <br />as follows: <br />Total Vegetation Cover 26.33 <br />Total Perennial Cover 23.03 <br />Relative Cover: <br />Grasses 6.93 <br />Forbs 8.43 <br />Shrubs 84.7$ <br />Canopy 84.7& * 23.0$ 19.5& <br />The condition of the reclaimed Red Canyon Mine Site <br />is taken from a vegetation survey performed August 18 & 19, <br />1992. The results of this vegetation report are as <br />follows: <br />• Total Vegetation Cover 47.8$ <br />Total Perennial Cover 34.93 <br />Relative Cover: <br />Grasses 21.73 <br />Forbs 28.1$ <br />Shrubs 50.23 <br />Canopy 50.23 * 34.93 17.53 <br />The Universal Soil Loss Equation will be used to <br />calculate the soil loss from the reclaimed mine site <br />and the natural conditions to determine if untreated <br />drainage from the reclaimed mine site 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 host-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 #5o dated January 1977 as follows: <br />-96c- New 11-25-92 <br />TP~l0 <br />rw.-. <br />