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Demonstration Areas Mine 3 contains three areas to which CYCC feels a demonstration to satisfy Rule • 4.05.2(2) may be applicable. These areas are shown on Map 4a (Hydrology and Sediment Controll. The demonstration consists of two parts; an assessment of actual on-the-ground conditions by means of the BLM Erosion Condition Classification System (Technical Bulletin #346), and an estimate of annual sediment yield by means of the "Universal Soil Loss Equation." Values obtained using the ECCS are compared the condition classes presented in the Technical Bulletin (#346). Those sites which fall into the stable, slight, or low moderate condition classes are considered to be satisfactory, as previously discussed in Minor Revision 90-11 (Commitment to Demonstration) Values obtained using the USLE are compared to those of undisturbed areas which are comparable in terms of slope length and gradient. The Universal Soil Loss Equation referenced earlier in the Exhibit is of the form • A = RKCLSP Where A =Annual Soil Loss in Tons per Acre per Year R =Rainfall Factor K =Soil Erodibility Factor C =Crop Management Factor LS= Slope Length/Gradient Factor and P =Erosion Control Practice Factor For each area involved in the demonstration~~s (both disturbed and undisturbed), average slope length and gradient was determined through assessment of current topographic maps and ground measurements. These average values were then used to determine the topographic factor ILSI for each area from the SCS Slope Effect Chart (Figure TR 90-06- 11. The only other factor not previously approved in other submittals is the cropping factor • (C), which is based on the percent canopy cover and the percent litter present. As seen in Table 90-6-15, the percent of litter/ground cover present may have a strong impact upon the C value selected. TR 90-06 Exhibit 3 - 42 Revised 11/16/90