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• The following calculations are presented to determine if untreated drainage from the reclaimed Coal <br />Ridge No. 1 Mine Irrigated Hayland Community is contributing suspended solids to streamflow or runoff <br />outside the permit area in excess of premising levels. <br />IRRIGATED HAYLAND <br />Versus Adjacent Area <br />Vegetation Data From Following Page 4-58vi <br />Adjacent Hayland <br />Total Vegetation Cover 93.1% <br />Litter 6.2% <br />Cover + Litter 99.3% <br />Reclaimed Hayland <br />Total Vegetation Cover 97.2% <br />Litter 2.5% <br />Cover + Litter 99.7% <br />USING THE UNIVERSAL SOIL LOSS EQUATION <br />• <br /> <br />It is assumed that all variables used in the USLE, except the C-factor, are constant relative to the adjacer <br />and reclaimed areas. Therefore vegetative condition is the key variable in making a determination that <br />potential sediment yield is less after mining than before mining. The "C' factor for the USLE is calculated <br />from Figure 7, from agronomy note #50 dated January 1977 as follows: <br />Figure 7 <br />G - Cover at surface is grass, grasslike plants, decaying compacted duff, or litter. <br />Percent Ground Cover 95-100% <br />"C" Factor = .003 for both the reclaimed and adjacent area. <br />USING THE UNIVERSAL SOIL LOSS EQUATION <br />A=RKLSCP <br />A is the soil loss in Tons/Acre/Year <br /> Baseline Reclaimed <br /> Adjacent Hayland <br />R =rainfall factor 30.00 30.00 <br />K = soil erodibility factor - Nihill channery loam 0.24 0.24 <br />LS =combined length slope factor <br />Irrigated Hayland • 400' Slope 10% Grade 2.80 2.80 <br />C =cropping management factor: <br />'C' -Crop Management -Baseline . <br />Ground Cover 99.3% 0.003 <br />'C' -Crop Management -Reclaimed <br />Ground Cover 99.7% 0.003 <br />P =erosion control practice factor 1.00 1.00 <br />Soil Loss <br />AREA R K LS C P <br />The above calculation demonstrates that untreated drainage from the reclaimed area will contribute the <br />same amount or fewer suspended solids to streamflow or runoff outside the permit area as untreated <br />drainage from the natural (baseline) surrounding premising area. <br />4-58v 06/01 <br />