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2 04.6 Geology Description; <br />7. A review of the site specific Geology baseline information contained in the permit currently does <br />not appear to extend into the PR7 expansion area. Rule 2.04.6(2) for surface mining activities <br />requires a description of the geology within the proposed area to be affected over the life of the <br />operation down to and including the first aquifer and other coal seams, if any, below the lowest coal <br />seam to be mined. Prior to mining in the proposed expansion area, the Operator will need to submit <br />a permit revision to the application that contains the information required in Rule 2.04.6(2). The <br />Division will add a stipulation to the approval of this permit revision to this effect. <br />Trapper Response to Comment 7: The geologic setting is the same for the permit extension area as that <br />presented in the Trapper Permit. Figure 2.7 -4 in the Trapper Permit presents the structure of the basin in <br />the area of the mine. Structure of the coal seams was reviewed for the permit extension area. The review <br />showed that the typical dip to the north in the northeastern portion of the Trapper permit area is changing <br />to the northwest in Section 28 T6N R90W. This change fits the regional structure change that is shown in <br />Figure 2.7 -4. Additionally, please see the response to comment 8. <br />2.04.7 Hydrology Description <br />8. Based on the surface and ground water analyses discussed in section 2.07 of the permit, it does not <br />appear the surface and ground water system of the expansion area has been analyzed. This <br />information is required for the proposed permit area and adjacent areas, not just area that are to be <br />disturbed. <br />a. For the expansion area please submit a description of the ground water hydrology for the <br />proposed permit and adjacent area in accordance with Rule 2.04.7(1)(a). <br />b. For the expansion area please update the surface water information contained in permit <br />section 2.7.4 with the information required from Rule 2.04.7(2)(a) and (2)(bxi). <br />Trapper Response to Comment 8: Ground water hydrology within the permit expansion area does not <br />dramatically change. The structure maps for I and R coal seams were used to aid in the extrapolation of <br />the water -level elevations for the HI and QR aquifers in the permit extension area. The structure map for <br />the H seam was used in the extension of the water -level elevations for the Third White Sandstone because <br />the base of this sandstone is near the top of the H coal. <br />The water -level elevations in the QR aquifer were extended in the permit extension area accounting for <br />the change in the dip of these beds from the north to the northwest. This structure change causes the <br />water level contours to curve to the northeast in the permit extension area resulting in ground -water flow <br />to the northwest instead of the northerly flow that occurs to the west of this area. Similar changes in the <br />flow directions in both the HI and Third White Sandstone aquifers also occur in the permit extension area <br />and to the north of the extension area. <br />Three ground -water monitoring wells are proposed to be added in the northeast corner of the permit <br />addition area. These wells would be completed in the alluvial, HI and QR aquifers in the permit <br />extension area. <br />Further relevant discussions to the hydrologic regime of the expansion area will be covered in the 2013 <br />Annual Hydrology Report, including extended Water -Level Elevation maps depicting the extent of <br />subsurface water and overall geologic trends. <br />