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For the simulations, a conservative approach was adopted that assumed a worst -case <br />scenario. Because there is a limited amount of technical data available for the hydraulic <br />and transport parameters of the geologic strata under the site, these parameters were <br />estimated using the best available geotechnical data available from the literature. Since <br />there is commonly a range of values associated with these hydraulic and geochemical <br />parameters, values that result in the highest transport rates were selected. <br />2.0 Site Description <br />2 <br />JD -9 Mine Report <br />Geoscience Services <br />The JD -9 mine is located southwest of Paradox Valley on the flanks of <br />Monogram Mesa. According to the geologic map for the area (Cater, 1954), the waste <br />pile for this mine will be located on the Brush Basin member of the Morrison Formation <br />(Figure 1). The rock units in this area dip to the southwest at approximately one degree. <br />The JD -9 mines the upper sandstone unit of the Salt Wash member of the Morrison <br />Formation that contains some groundwater as evident by dewatering operations at the <br />mine. There is a small spring located to the south of the mine named Fawn Spring. <br />Visual inspection of the spring indicates small seepage faces that discharge only a few <br />gallons of water per day. Consequently, it is expected that the spring has only a minimal <br />effect on groundwater flow in the area and any movement of groundwater in the upper <br />sandstone member of the Salt Wash Member or the underlying Entrada Formation will be <br />controlled by the regional geologic structure. Consequently, any potential discharge of <br />groundwater from the mine site will occur in Bull Canyon located to the southwest. <br />The potential transport of constituents of concern from the JD -9 site will occurs as <br />horizontal transport following the regional dip of the rocks through the Upper Salt Wash <br />sandstone with leakage downward eventually reaching the Entrada Sandstone. <br />Comparisons with modeling conducted at the SM -18 mine will consider the differences <br />in the hydrogeology when evaluating the environmental impacts at the JD -9 mine site. <br />