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DRMS present wildlife monitoring results. <br /> Sedimentology <br /> The condition of the sediment ponds and any needed maintenance on the ponds receiving runoff from the <br /> bond release parcels were evaluated. Ponds receiving runoff from the bond release parcels are not <br /> receiving flow from affected lands not under consideration for bond release at this time. In order to meet <br /> CDRMS Regulation 3.03.1(3)(b), SPL provided a RUSLE (Revised Universal Soil Loss)demonstration <br /> to demonstrate sediment contributions to surface water from post mining reclamation activities. SPL's <br /> bond release utilized the RUSLE equation to predict and compare the gross annual erosion per acre on the <br /> reclaimed and vegetated parcels and compare them to the undisturbed reference areas. The RUSLE is an <br /> empirical formula approximating expected sediment yield from a parcel of land. It is reasonable to <br /> hypothesize that the RUSLE is useful for discriminating between two significantly different yield rates. <br /> For the bond release parcels in SL6, SPL calculated a sediment yield rate in the reference areas and a <br /> postmining rate in the bond release parcels as presented in the bond release application. The difference <br /> between these two calculated rates illustrates that the postmining rate of sediment yield is less than the <br /> yield in the reference areas. This conclusion is only valid if reasonable variables are employed in the <br /> RUSLE calculations. The variables employed in the RUSLE equation and their definitions are presented <br /> in table II below. <br /> Table IL R USLE Variables and their Definitions <br /> Variable Definition <br /> R Climatic erosivity factor due to precipitation <br /> K Soil erodibility under a standard condition <br /> LS Slope length and steepness factor <br /> C Cover management/land use <br /> P Support practices factor <br /> R Factor.Erosivity of Rainfall and Runoff <br /> The R Factor quantifies the effect of raindrop impacts and <br /> reflects the amount and rate of runoff associated with <br /> annual precipitation. The value used for this factor was <br /> obtained from the EPA Rainfall Erosivity Factor Calculator. <br /> The calculator accounts for the mine location and <br /> disturbance dates to relate back to historic rainfall data. <br /> K Factor, Soil Erodibility <br /> The K Factor indicates the relative susceptibility of surface <br /> soil to water erosion. Values can vary from 0.0 to 0.70. The <br /> higher value indicates higher erosion susceptibility. In Tab <br /> 09, of the baseline Soil Study conducted for the mining <br /> permit,the K factor, soil erodibility,was determined to be <br /> anywhere from 0.19 to 0.36. This demonstration utilized <br /> �•.. the value of 0.28. <br /> LS Factor, Hillslope-Length and Gradient <br /> The LS Factor is the slope length factor representing the <br /> effect of the slope length on erosion relative to the slope <br /> Permit Number C1982057 Prepared by: R.Reilley MS,GISP <br /> SL6 Phase II and III Page 9 of 16 <br />