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<br /> <br />Memo: Deserado AHR - 3 - February 25, 1986 <br />The depletion and and/or degradation of the alluvial aquifer located along the <br />White River is no longer an issue nor substantial concern. This is because <br />the presence of Kenney Reservoir, which has flooded the alluvium in the <br />vicinity of the mine, attenuates all effects of ground water withdrawals from <br />the alluvium. <br />The effects of mining to adjacent, unmined coal/siltstone facies water levels <br />appear to be negligible. Water levels drop rapidly when mining intercepts the <br />up-gradient equipotential surface (normal to flow) of this facies. As mining <br />begins to parallel the flow the rapid drop decreases, but water levels <br />continue to drop slowly. <br />The effects of mining to the potentiometric surfaces of the upper and lower <br />facies is not defined, as data from the two most potentially affected wells is <br />missing. <br />As the Deserado Mine begins full production, the Division, in the future, <br />should be concerned with increased mine inflows, particularly along the east <br />and west mains; accurate, reliable monitoring and reporting of all required <br />wells; subsidence impacts to surface waters over longwall panels. <br />To accurately address these concerns, WFU should commit to water <br />inflow/consumption studies at the mine. These studies should be done as an <br />ongoing process. These studies should include the following data: Total <br />amount of mine inflows, consumptive underground use of water, quantity and <br />quality (pH, specific conductance, temperature) of portal discharges. Any <br />increases in pond discharges to the Scullion Gulch due to portal discharges <br />should also be reported. <br />The Division approved hydrologic monitoring and reporting requirements <br />(frequency of measurement and parameters monitored) should be followed. <br />Finally, an accurate, reliable method of monitoring aquifer characteristics in <br />the Red Wash alluvium must be established. A series of wells - paralleland <br />perpendicular to Red Wash - in conjuction with surface water gage sites, would <br />be an acceptable method of determining the affects of longwall subsidence to <br />the alluvial flow system. <br />If you have any questions, or if I can be of further assistance, please <br />contact me. <br />/pjh <br />7842 <br />