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2.05.6 Mitigation of the Impacts of Mining Operations <br />Groundwater <br />Most precipitation is lost to evaporation from the soil or is transpired by <br />vegetation before it can percolate to the water table and recharge the aquifer. <br />Most precipitation recharge likely occurs during periods of snowmelt or prolonged <br />rainfall when water is available for percolation and evapotranspiration rates are <br />small. In clayey soils, percolation is slow, and most soil water is held at shallow <br />depth, where it can be lost to evapotranspiration. Intense precipitation produces <br />surface runoff and low percolation. <br />The virtual lack of alluvial groundwater in the area would indicate the percolation <br />rate in permit and adjacent area is low. East Salt Creek is the only location in the <br />permit and adjacent area where alluvial groundwater is continuous. The source <br />for this groundwater is most likely from stream flow infiltration rather than <br />recharge from precipitation. <br />A coal mine waste pile will be constructed west of the facilities. The phase I coal <br />mine waste pile has a footprint of about 65 acres. The average precipitation in <br />the area is 8.8 inches based on the Fruita weather station. As stated above most <br />precipitation is lost to evaporation and transpiration. Assuming 5% of the rainfall <br />leaches through the pile during the year, the resultant flow would be about 1.5 <br />gpm. <br />Volume III, Tab 6 presents an analysis of the cameo roof and floor from three <br />exploration holes drilled in 1996. There is also an analysis of waste coal from the <br />McClane Canyon Mine Loma and Mine yard. The McClane Canyon mine data is <br />relevant to the analysis because mining will occur in the same seam as the <br />McClane Canyon Mine and is only 4 miles south of the Red Cliff Mine. This data <br />will represent the quality of the gob pile leachate. Following is a summary of the <br />data. <br /> Roof & Floor Mine Yard Loma Yard <br />pH (su) 7.8 7.3 6.8 <br />EC (umhos/cm) 2800 3410 2940 <br />ABP (t/1 000t) 78 24.9 10.4 <br />Iron (mg/1) 69.7 6.5 7.73 <br />Manganese (mg/1) 4.74 2.9 1.81 <br />EC is electrical conductivity. ABP is acid base potential. <br />• <br />Permit Application 2.05-101 06/08