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thereby increasing the time to flood the workings; however, it is uncertain if <br /> the drainage out of the mine area through the coal seam will exceed the <br /> drainage into the mine from overlying strata. If outflow does not exceed <br /> inflow, some discharge from the portals may occur. The permittee has <br /> proposed backfilling of the portals and construction of bulkheads upon closure <br /> of the mine, minimizing the possibility for discharge of water. <br /> In the northern sections of the mine plan area is a large coal refuse disposal <br /> area. Drill hole data indicate that there is no ground water within 44 feet of the <br /> ground surface in the disposal area, and recharge to ground water in the <br /> Mesaverde Group is minimal. Infiltration of water through the refuse pile will <br /> be minimized by covering the compacted refuse with 30 to 48 inches of the best <br /> available non-toxic material. Impacts to the ground water system are not <br /> expected to be significant due to the relatively impermeable nature of the refuse <br /> and the low water table. <br /> The development and reclamation of the cuts and fills in the portal areas should <br /> have no impact on the bedrock aquifer system. Recharge of the aquifers does <br /> not occur in these areas due to surface water control systems, so possible <br /> degradation of the ground water by infiltrating waters is unlikely. The fill <br /> material itself is generally of suitable quality as a topsoil substitute except for <br /> SAR values which are up to twice as high as defined in the Wyoming <br /> Guidelines for suitability. As water flows through the fill, total dissolved solids <br /> may increase due to soluble salts; however, this occurs naturally within the <br /> existing ground water region. The fill does not contain materials that create a <br /> toxic leachate. Water that infiltrates the fill may reach Scullion Gulch. <br /> However, due to the small area of disturbance relative to the entire drainage <br /> basin for Scullion Gulch, this will be a very minor contribution of flow in the <br /> creek. <br /> The permittee will be obtaining part of the required water supply from the <br /> White River Lagoon, as discussed earlier. Approximately 552 ac. ft. per year <br /> (601 gpm) will be pumped from the lagoon to a head tank in the D-Portal area. <br /> This is less than one percent of the low flow of the White River. Therefore, <br /> impacts will not be significant. <br /> Recharge of the ground water is not expected to be impacted significantly by <br /> the proposed mining operation. Most of the recharge area for the Mesaverde <br /> aquifers is outside of the mine plan area. It is possible that surface fracturing <br /> resulting from subsidence could increase recharge to the Upper Williams Fork. <br /> However, these cracks, if they occur, are expected to exist for only a short <br /> period of time before they seal up. <br /> Recharge of the White River alluvium by bedrock aquifers is not considered to <br /> be significant because of the low transmissivities of the aquifers. The permittee <br /> has estimated that total discharge could be 1.3 gpm through bedrock aquifers to <br /> 27 <br />