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with sediment relatively quickly. Actual interruption of surface flows should not be <br />s ignific ant. <br />Stock ponds located above the mine, and within the permit area, could also be impacted by <br />subsidence; however, significant impacts are unlikely, due to the approved subsidence <br />protection plan for the Bowie No. 2 Mine which should minimize subsidence beneath any <br />of the stock ponds. These stock ponds are owned by BRL. <br />The required sediment and drainage control plan for the Bowie No. 2 Mine must be <br />constructed and maintained as permitted. This system will protect all offsite areas from <br />any detrimental impacts from sediment or surface runoff originating on the mine site. <br />It is possible that offsite areas might receive discharge from such sources as underground <br />mine water, refuse pile leachate, or other mine -related activities. Such parameters as iron <br />and oil and grease are strictly regulated by point source discharge permit standards (issued <br />by the Colorado Department of Public Health and Environment) limitations. However, <br />mine -related discharge may exhibit increased levels of total dissolved solids. The Bowie <br />No. 2 Mine permit document provides reasonable predictions of mine -related discharge <br />quantity and quality, specifically emphasizing possible increases in total dissolved solids <br />to the 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 boundary, <br />could be impacted by subsidence. Specifically, subsidence could temporarily de -water <br />these zones; however, these water sources are not used, and recharge should occur over <br />time. It is also possible that the local bedrock groundwater quality could be impacted by <br />elevated total dissolved solids concentrations, as the mine fills with water following <br />mining, and as the water infiltrates to surrounding groundwater. Impacts within the permit <br />area should be minimal, due to the relative lack of useable groundwater, and due to the <br />vertical 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 alluvial systems <br />downgradient form the mine should not receive sufficient mine water drainage to create <br />any impacts. <br />IV. Topsoil <br />Information regarding baseline soil studies may be found in Section 2.04.9 of the permit. <br />Information regarding the salvaging and replacement of topsoil may be found in section 2.05.4 of <br />the permit. Except for one situation, all available topsoil will be salvaged from areas to be <br />disturbed by mining prior to disturbance. During reclamation, topsoil will be replaced in a 12 <br />inch deep layer. Six inches of topsoil will be replaced on top of 3.5 feet of fill over the reclaimed <br />gob pile. <br />A. The Division proposes to approve alternative procedures for topsoil protection at one <br />location. Approval of Permit Revision No. 6 permitted a variance from salvaging all of <br />the topsoil at the train loadout coverfill stockpile. BRL will salvage the top two to three <br />inches of topsoil and then will place geotextile fabric on the coverfill area. Soil from the <br />cut operations for the train loadout will, then, be placed on top of this geotextile material <br />(4.06.1(2)). <br />29 <br />