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K Factor. Soil Erodibili <br />The K Factor indicates the relative susceptibility of surface soil to water erosion. Values can vary <br />from 0.0 to 0.70. The higher value indicates higher erosion susceptibility. With in Addendum 5 <br />of Tab 09 of the baseline Soil Study conducted for the mining permit, the K factor, soil <br />erodibility was determined to be any where from 0.19 to 0.36. For the purpose of this <br />demonstration an average was taken and a value of 0.28 was used. <br />LS Factor, Hill slope -Length and Gradient <br />The LS Factor is the slope length factor representing the effect of the slope length on erosion <br />relative to the slope steepness. This value represents how erodible the particular slope length and <br />steepness is relative to a 72.6 ft long and 9% steep slope unit plot. These values were unique to <br />each parcel and were determined using the RUSLE 1.06c application with the inputs of the BR <br />parcel lengths and slope gradient values. <br />C Factor, Cover Management <br />The C Factor represents the effects of plants, soil cover, soil biomass, and soil distributing <br />activities of erosion. The C factor accounts for all surface cover including non -plant material. <br />Data from the vegetation report in attachment D was used as inputs with in the RUSLE 1.06c <br />application to determine the C Factor of 0.003 used for this demonstration. <br />P Factor, Support Practice <br />The P factor reflects the impact of support practices on the annual average erosion rate. A <br />conservative value of 1 indicates that there is no consideration for deposition where as a value of <br />0 indicates that no sediment left the slope. In our scenario we know that sediment leave the slope <br />but hope that our practices help reduce the sediment leaving so we assumed a value of 0.9. <br />Table 5: SL8 Yoast Bond Release RUSLE Variables and Calculations <br />Bond <br />Release <br />Polygon <br />Acres <br />R <br />K <br />Length of <br />Segment <br />Slope <br />Gradient <br />LS <br />C <br />P <br />A <br />5 <br />3.63 <br />16 <br />0.28 <br />670 <br />15 <br />4.27 <br />0.003 <br />0.9 <br />0.05165 <br />11 <br />0.8 <br />16 <br />0.28 <br />115 <br />35 <br />6.03 <br />0.003 <br />0.9 <br />0.072939 <br />27 <br />2.14 <br />16 <br />0.28 <br />800 <br />8 <br />1.68 <br />0.003 <br />0.9 <br />0.020321 <br />60 <br />13.94 <br />16 <br />0.28 <br />480 <br />12 <br />2.72 <br />0.003 <br />0.9 <br />0.032901 <br />63 <br />0.7 <br />16 <br />0.28 <br />440 <br />16 <br />4.05 <br />0.003 <br />0.9 <br />0.048989 <br />64 <br />0.62 <br />16 <br />0.28 <br />300 <br />14 <br />2.94 <br />0.003 <br />0.9 <br />0.035562 <br />65 <br />3.76 <br />16 <br />0.28 <br />485 <br />25 <br />7.63 <br />0.003 <br />0.9 <br />0.092292 <br />70 <br />1.97 <br />16 <br />0.28 <br />350 <br />25 <br />6.68 <br />0.003 <br />0.9 <br />0.080801 <br />75 <br />1.87 <br />16 <br />8 <br />25 <br />20 <br />1.85 <br />0.003 <br />0.9 <br />0.022378 <br />76 <br />2.15 <br />16 <br />Lu420 <br />18 <br />4.69 <br />0.003 <br />0.9 <br />0.05673 <br />SL-8 - 12 <br />