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refuse disposal areas, location and extent of surface disturbance and <br />hydrogeologic conditions associated with underground mine locations. <br />During the first two permit terms, the West Elk Mine mined the F Seam. <br />During the third permit term, West Elk mined the B Seam exclusively. <br />Activity in these seams involve longwall mining methods, with very little or <br />no activity in the F Seam. During the next permit term West Elk plans to <br />mine the B-seam for most of the period, with access to and development of <br />the E-seam beginning towazd the end of the 5-year permit term. <br />The Probable Hydrologic Consequences section of the permit is divided into <br />two main subsections: Groundwater Effects and Surface Water Effects. <br />a. Groundwater Effects <br />There are no immediate demands on groundwater in the vicinity of the <br />West Elk Mine. Domestic water for the mine will be supplied by surface <br />water from the North Fork of the Gunnison River, as there is limited <br />potential to use groundwater as a resource. The primary concern with <br />groundwater quality and quantity is the possible impact on springs, the <br />potential for mine water discharge and groundwater quality impacts in <br />the mine facilities azea. <br />The underground mining methods in use at the West Elk Mine can affect <br />groundwater in two ways. First, development mining in areas where <br />groundwater is present in or near the coal seam can cause localized <br />movement of this water into the mine workings. To date, groundwater <br />movement of this type has occurred in areas of low cover which aze <br />highly fractured (neaz outcrops and near stream channels) and where <br />sandstone channels bearing water immediately overlie the coal seam. <br />Secondly, longwall mining can cause subsidence and the fracturing of <br />overlying groundwater aquifers. Again, water usually moves into the <br />mine workings. The permeability of the F and B Seam and overlying <br />strata is very low and the areal extent and quantity of water stored in <br />these units is small. <br />Prior to construction of the mine, the applicant made an estimate of mine <br />inflow by using preliminary pump test results and the McWhorter <br />hydrogeologic model. The mine flow estimates assist in identifying the <br />magnitude of mine dischazge and to assess the potential impact on natural <br />patterns of groundwater recharge and dischazge. <br />In the past, the West Elk Mine has experienced three types of mine <br />inflows. The first type of inflow is due to primary permeability which is <br />groundwater flow through the competent portions of the F Seam and <br />lower Barren Member. The second type of inflow occurs in the coal <br />seam and overlying Barren Member in azeas of shallow overburden. This <br />51 <br />