2009-10-13_PERMIT FILE - C1991078A (3)

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CANOPY NO APPRECIABLE CANOPY PERCENT GROUND COVER 40.0% 48.8% 60.0% No G 0.100 0.074 0.042 appreciable Adjacent "C" Factor .074 canopy RECLAIMED AREA - "C" FACTOR No appreciable canopy. Canopy is assumed to be the cover contributed by trees and shrubs. Based on the 2009 vegetation study the combined tree and shrub cover totals 9.4%. The percent ground cover for the reclaimed area shown on the preceding page is 62.8%. Use figure 7 identified above and interpolate to determine the C factor for 62.8% cover. CANOPY NO APPRECIABLE CANOPY PERCENT GROUND COVER 60.00% 62.80% 80.00% No G 0.042 0.038 0.013 appreciable Reclaimed "C" Factor.038 canopy USING THE UNIVERSAL SOIL LOSS EQUATION A=RKLSCP • A is the soil loss in Tons/Acre/Year Adjacent Reclaimed R = rainfall factor 30.00 30.00 K = soil erodibility factor - Nihill channery loan 0.24 0.24 LS = combined length slope factor 0.62 0.73 C = cropping management factor: "C" - Crop Management - Adjacent Canopy 8.7% Cover - Grass 10.2% Ground Cover 48.8% 0.074 "C" - Crop Management - Reclaimed Canopy 9.4% Cover - Grass 21.2% Ground Cover 62.8% 0.038 P = erosion control practice factor 1.00 1.00 Soil Loss AREA R K LS C P A 30 0.24 0.62 0.074 1.0 0.33 Adjacent Area 30 0.24 0.73 0.038 1.0 0.20 Reclaimed Area • It can be seen from the above calculation that the revegetated area of the reclaimed mine site may loose about 0.20 tons per acre per year to erosion. The baseline conditions may loose about 0.33 tons per acre per year to erosion. The above calculation demonstrates that untreated drainage from the reclaimed area will contributes fewer suspended solids to streamflow or runoff outside the permit area as untreated drainage from the natural surrounding premining area. TR-10 2.05-8vi 7R - /0 R Aprle 08/09