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rate is 100 gpm or 0.22 cfs. <br />The quality of the mine water as presented in the Hydro-Geo report indicates it is of <br />bicarbonate, sulfate type with a relatively low concentration of total dissolved solids. <br />Mine water monitoring from 2001 to 2005 reports Electrical Conductance (EC) values <br />ranging from 540 to 5700 umho/cm with a average of 1918 and a pH range of 7.3 to <br />8.69. <br />A coal mine waste pile is planned for the area south and west of the existing sediment <br />pond. The coal mine waste pile has a footprint of 1.6 acres. The average precipitation in <br />the area is 18.1 inches based on the Ashford Canyon rain gage. Assuming all of the <br />rainfall leaches through the pile during the year, the resultant flow would be 1.5 gpm. This <br />is a very conservative analysis since coal mine waste has arun-off curve number around <br />90. The amount of leachate produced by the pile would actually be significantly less than <br />1.5 gpm. Table 2.1-6 presents an analysis of the coal mine waste. The coal mine waste <br />has a pH of 7.29 su and an EC of 3,410 umhos/cm. In order to evaluate the potential <br />impacts of the gob pile leachate, it is necessary to combine the leachate with the mine <br />water to get a combined flow rate and combined conductivity. Although the gob pile is not <br />yet in place at the time of this writing, and therefore doesn't impact the surface or <br />groundwaters, it is necessary to evaluate the contribution of the gob pile leachate as if it <br />were cohtributing to the mine water flow rate and conductivity. Discharge from the <br />sediment pond is disregarded in this analysis as the flow is infrequent, in the last three <br />years, the sediment pond has only discharged three times, and is therefore not considered. <br />Therefore, combining 1.5 gpm with an EC of 3410 umhos/cm to 0.08 gpm with an EC of <br />480 umhos/cm to 100 gpm flow (mine water flow rate) with a 1918 umhos/cm results in a <br />combined flow of 101.58 gpm (0.23 cfs) with an EC of 1970 umhos/cm. These combined <br />values (mine water discharge, sediment pond seepage and gob pile leachate) from here <br />forward will be referred to as `combined' instead of mine water flow rate. <br />Data gathered for SW-1 and GW-3 are presented below. The Division's 1987 Material <br />Damage guidelines require any measured salinity values over 1000 umhos/cm be <br />reported as `suspect' values. Since baseline values for SW-1 and GW-3 far exceed the <br />Division's `suspect' levels, the Operator compiled data in order to demonstrate <br />combined discharge does not add salinity to the already high values, rather, can only <br />lower the salinity in SW-1 and GW-3 during the irrigation season. By improving the <br />salinity of the waters in East Salt Creek and the East Salt Creek alluvium, downstream <br />farmers will not suffer loss of production due to the addition of the combined discharge. <br />The following table presents the impact the combined discharge would have on the EC <br />in East Salt Creek measured above the McClane Canyon Mine at SW-1 during irrigation_ <br />season (April -October): <br />• <br />Appendix N - TR-16 - 3 - 10/08 <br />