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The cover factor in the USLE equation accounts for the effect of plant and litter cover on <br />the ground surface in reducing erosion by intercepting raindrops and reducing direct <br />contact with the soil. For the varying vegetation types such as that at the Carbon Junction <br />Mine, Tables 4 and 6 were used in conjunction with the vegetation data to develop the <br />appropriate factors. <br />Within the reclaimed areas, Table 6, "C" Factors for Permanent Pasture and Rangeland <br />from the U.S. Department of Agriculture Technical Note #50 (revision #2): Universal Soil <br />Loss Equation was used to select the appropriate C factor. The reclaimed and revegetated <br />areas have no appreciable canopy of trees and/or shrubs and the cover at the ground <br />surface (vegetation and mulch) is 90 percent. This combination of characteristics yielded <br />an interpolated table value of 0.06 as the C factor for the North Pit, Haul Road, and <br />Equipment Area reclaimed areas. <br />Table 6. was also employed to ascertain the appropriate C factor for the native areas <br />adjacent to the North Pit and Haul Road. These native areas are predominantly pinyon- <br />juniper woodlands, with appreciable tree canopy and little low brush understory. There is <br />approximately 50 percent canopy coverage and the ground surface cover is predominantly <br />graminoid in nature. The percent ground cover was estimated at 30 percent, yielding a C <br />value for these areas of 0.13. <br />Table 4, Crop Management Factor "C" Western Colorado from Technical Note #50 was <br />used to select a C factor for the agricultural area adjacent to the reclaimed and revegetated <br />Equipment Area. This area is in dryland winter wheat production with no fallow cycle. It <br />was estimated that 200-500 pounds of residue is returned to the soil during tillage. These <br />characteristics yield a C factor value of 0.31 for this area. <br />CONTROL PRACTICE FACTOR (P) <br />This factor is used to identify those soil conservation and sediment control practices which <br />affect the level of sediment generated from a site (e.g., ditches, ponds, sediment traps). In <br />this comparison we are interested in the sediment generated from the reclaimed site above <br />such structures, as if they had been removed. Likewise, for the undisturbed area, there are <br />no such controls. Therefore, for the purposes of our comparison, a value of unity (one) <br />will be assigned this factor, rendering no impact to our calculations. <br />Oakridge Energy Carbon Junction Mine Page 5 <br />Sediment Pond Sedimentology Demonstration