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per year. Mine inflows, mine drainage and dewatering volumes are approximately <br />4.7 percent of possible flows from the affected strata within the groundwater <br />basin. <br />Based upon this comparative approach, mine inflows do not represent a <br />significant volume relative to ground water flows within the basin. It should also <br />be noted that figures for Southfield Mine inflow rates may be somewhat high, <br />reflecting the additional contributions of vertical seepage through subsidence <br />fractures from overlying abandoned and flooded mine workings in the Vento Coal <br />Seam. <br />It is anticipated that any effects on downgradient groundwater flows will be <br />temporary and will be limited to the period of active mining and dewatering and a <br />relatively short interval thereafter. Upon completion of mining, EFCI will abandon <br />and seal the underground mine workings. With relatively constant inflows to the <br />workings, the mine will gradually flood and recharge to downgradient areas will <br />be re-established. In addition, there is the potential for localized increases in <br />downgradient flows as a result of increases in hydrostatic pressure as water <br />builds-up in the abandoned workings and increased availability of water in the <br />resulting perched groundwater reservoir provides a source of recharge. <br />As EFCI has developed certain new mining areas, there have been significant <br />increases in groundwater inflows, with measured flow rates well above normal <br />inflow rates experienced in other active working areas. These elevated mine <br />inflows have been documented in Southfield's Annual Hydrology Reports and are <br />believed to represent vertical seepage through subsidence fractures which <br />intersect overlying abandoned and flooded mine workings on the Vento Coal <br />Seam approximately one hundred feet above the interval disturbed by <br />Southfield's operations. If this is assumed to be the case, Southfield's ongoing <br />development and mining activities may result in some dewatering of perched <br />groundwater aquifers contained in these overlying mine workings. <br />This potential hydrologic impact is not expected to be significant since the <br />associated groundwater resources have no history of beneficial use. Primary <br />factors limiting use include depth, and the availability of alternative surface and <br />groundwater sources which are more accessible and <br />MR-50 2, O5. 6-42 Revised -June 2003 <br />