Laserfiche WebLink
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 document <br />provides reasonable predictions of mine-related discharge quantity and quality, <br />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 and the Rollins Sandstone <br />located considerably below the mining elevation. Local alluvial systems <br />downgradient form the mine should not receive sufficient mine water drainage to <br />create any impacts. <br />IV. Topsoil <br />Information regarding baseline soil studies maybe found in Section 2.04.9 of the permit. <br />Information regarding the salvaging and replacement of topsoil maybe found in section <br />2.05.4 of the permit. Except for one situation, all available topsoil will be salvaged from <br />areas to be disturbed by mining prior to disturbance. During reclamation, topsoil will be <br />replaced in a 12 inch deep layer. Six inches of topsoil will be replaced on top of 3.5 feet <br />of fill over the reclaimed gob pile. <br />A. The Division proposes to approve alternative procedures for topsoil protection at <br />one location. Approval of Permit Revision No. 6 permitted a variance from <br />salvaging all of the topsoil at the train loadout coverfill stockpile. BRL will <br />salvage the top two to three inches of topsoil and then will place geotextile fabric <br />on the coverfill area. Soil from the cut operations for the train loadout will, then, <br />be placed on top of this geotextile material. (4.06.1(2)). <br />B. The Division waived the requirement for clearing of small shrub and grass-type <br />vegetation cover prior to topsoil removal. The applicant has demonstrated that <br />inclusion of vegetation cover in salvaged topsoil is not detrimental to soil <br />productivity consistent with the post-mining land use. Large tree and shrub <br />vegetation was removed prior to topsoil salvage. <br />29 <br />