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Mine. The analysis is presented in Section 2.05.6(3)(b)(iii) of the permit <br />application document. Possible hydrologic impacts to the local surface and <br />ground water systems are summarized below. <br />Surface water systems directly above the mine workings within the permit area <br />could be minimally impacted due to mine subsidence. Surface cracking resulting <br />from subsidence could occur within the ephemeral and intermittent stream <br />channels which overlie the mine; however, such impacts should be minimal and <br />surface cracks should fill with sediment relatively quickly. Actual interruption of <br />surface flows should not be significant. <br />Stock ponds located above the mine, and within the permit area, could also be <br />impacted by subsidence; however, significant impacts are unlikely, due to the <br />approved subsidence protection plan for the Bowie No. 2 Mine which should <br />minimize subsidence beneath any of the stock ponds. These stock ponds are <br />either owned by BRL or addressed in the approved water augmentation plan. <br />The required sediment and drainage control plan for the Bowie No. 2 Mine has <br />been constructed and maintained as permitted. This has been designed to protect <br />all offsite areas from any detrimental impacts from sediment or surface runoff <br />originating on the mine site. <br />It is possible that offsite areas might receive discharge from such sources as <br />underground mine water, refuse pile leachate, or other mine - related activities. <br />Such parameters as iron and oil and grease are strictly regulated by point source <br />discharge permit standards (issued by the Colorado Department of Public Health <br />and Environment) limitations. However, mine - related discharge may exhibit <br />increased levels of total dissolved solids. The Bowie No. 2 Mine permit <br />document provides reasonable predictions of mine - related discharge quantity and <br />quality, specifically emphasizing possible increases in total dissolved solids to the <br />hydrologic system. The predictions indicate that any such increases should not be <br />significant, and downstream uses should not be impacted. <br />Perched groundwater, located above the mine workings and within the permit <br />boundary, could be impacted by subsidence. Specifically, subsidence could <br />temporarily de -water these zones; however, these water sources are not used, and <br />recharge should occur over time. It is also possible that the local bedrock <br />groundwater quality could be impacted by elevated total dissolved solids <br />concentrations, as the mine fills with water following mining, and as the water <br />infiltrates to surrounding groundwater. Impacts within the permit area should be <br />minimal, due to the relative lack of useable groundwater, and due to the vertical <br />separation which exists between the D -2 coal seam, the B -2 coal seam and the <br />Rollins Sandstone located considerably below the mining elevation. Local <br />alluvial systems downgradient form the mine should not receive sufficient mine <br />water drainage to create any impacts. <br />24 <br />