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Dewatering Evaluation Report <br />Varra Pit 122 <br />Weld County, Colorado <br />Page 5 <br />Table 1— Lined Pit Water Level Comparison Points <br />1 4790.97 4789.92 0.1.05' <br />2 4790.23 4790.88 0.65' <br />3 4791.96 4792.28 0.32' <br />4 4795.62 4797.52 1.90' <br />5 4798.97 4799.80 0.83' <br />6 4797.69 4799.06 1.37' <br />Results <br />A review of plates 7-11 show that the groundwater hydrology less than one-half mile east of Pit <br />122 is not affected by any pumping scenario. The model predicts a drawdown of 4 to 5 feet 1,500 <br />feet north of Pit 122 and similar conditions approximately 1,000 feet south of Cell B in Pit 116. The <br />cessation of pumping from Cell A of Pit 116 appears to allow recharge to the west of the pit. The <br />lining of this pit may also create a protective barrier (to the west) to pumping associated with Pit <br />122. <br />A review of Table 1, shows that the lining of mined pits will have a de minimis effect on <br />groundwater hydrology. Predicted post lining head levels immediately up and downgradient of the <br />barrier walls are within the range of normal seasonal water table elevation changes. <br />Conclusions <br />The results of analytical and numerical solutions indicate that the proposed mine dewatering <br />activities will not adversely affect the regional groundwater hydrology. With the exception of <br />shallow alluvial deposits just to the west of Pit 122, the saturated aquifer thickness in all other <br />areas outside of the Pit 122 development is sufficient to provided adequate well yields. The <br />predicted drawdown associated with the Pit 122 mine dewatering model represents the worst