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The impact of the proposed mine on ground water will be localized, with no <br />significant impact expected on a regional basis. This is due primarily to the <br />small quantity of ground water in the area. <br />Water encountered within the mine will be utilized underground for dust <br />suppression. As a result, only those inflows that temporarily exceed storage <br />capacities and mine use requirements would potentially be discharged to the <br />surface and lost from the ground water system. Pumping from approved <br />mine water discharge locations ceased upon the sealing of the D seam <br />northern longwall district in 1996. Although dewatering could be <br />accomplished by installation of a submersible pump, dewatering is not <br />currently anticipated. If mine water discharge were to occur, there would be <br />no loss to the hydrologic system, being that ground water in the area is <br />tributary to the White River. <br />Since January of 1997, prep plant thickener water has been disposed <br />underground within down -dip, sealed sections of the D seam mine. No <br />discernible effects on surface water or ground water quality are anticipated, <br />although water levels will be reestablished sooner than would otherwise be <br />the case. <br />Subsidence effects include fracturing of the material overlying the coal for a <br />distance of 30 to 40 feet due to caving of the roof material and surface <br />subsidence with possible development of tension cracks on the surface due to <br />differential settling. Observed ground water inflows during mining have <br />been approximately 50 gpm. In fractured areas, increased flows of 100 to <br />300 gpm may be encountered for a short period of time. These flows will <br />diminish as equilibrium is reestablished. Due to the low transmissivities of <br />the aquifers, if caving should create a hydrologic connection from the mine to <br />an aquifer within 30 to 40 feet of the coal, the additional inflow will be <br />minimal. It is not probable that fracturing from the mine to the surface will <br />occur as a result of subsidence and cause the flow of surface water to the <br />mine. <br />Subsequent to completion of mining, the ground water will slowly reestablish <br />its pre- mining water levels. Due to caving of the roof materials into the <br />mine, an area of increased permeability will exist within the mine that will <br />act as a "sump area" until equilibrium is established. However, due to the <br />small quantity of water in the aquifers being discharged to the White River <br />and its tributaries, the lack of ground water usage in the area, and the poor <br />quality of ground water, potential impacts to flow in the White River will be <br />minimal. <br />The possibility exists for water to discharge from the portals once the mine <br />workings have become completely flooded. The portals are up -dip in the <br />mine, and drainage will tend to move down dip of the mine and coal seam, <br />34 <br />