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• <br />Probable Hydrologic Consequences New Elk Mine 20 <br />Results from the packer tests are summarized by lithology in Table 12 and by borehole in Table 13. <br />Testing data and plots of the pressure response for the tests are presented in Appendix B. <br />Packer permeability tests indicate that the average hydraulic conductivities of the Allen, Apache, Red, <br />Upper Bingham Canyon, Blue, Green, and Yellow coal seams are similar and range from 0.43 to 0.51 <br />ft/day. The permeability of the Maxwell seam is lower with an average value of 0.013 ft/day. Clastic rocks <br />including sandstone, siltstone, mudstone, and shale usually have lower permeability than the associated <br />coals. Exceptions to this generalization include the interval between the Allen and Apache beds, which has <br />an average hydraulic conductivity of 1.28 ft/day, and the roof of the Blue coal seam, which has an average <br />hydraulic conductivity of 0.54 ft/day. <br />Water level measurements during packer testing indicate that heads in the coal seams are generally lower <br />than in the surrounding rocks (Table 14). In many cases, the observed vertical gradients are exceptionally <br />high and exceed unity. The high vertical gradients are most likely related to groundwater pumping from <br />CBM production wells or dewatering activities for the existing New Elk underground workings. The <br />presence of high vertical gradients indicates that permeability is low perpendicular to bedding and limits <br />the flow of groundwater from the surrounding clastic rocks to the coal beds. <br />Table 12. Packer Test Summary by Litho/ogy <br />Unit <br />Number of Tests <br />Hydraulic Conductive (ft/day) <br />Range <br />Average <br />Allen <br />Roof <br />Coal <br />Floor <br />2 <br />3 <br />2 <br />1.10 to 1.46 <br />0.35 to 0.64 <br />0.001 to 0.004 <br />1.28 <br />0.51 <br />0.003 <br />4164A.110130 Whetstone Associates <br />PR 02 <br />Exhibit 8(4) Page 141 <br />Revised 1/31/11 <br />Roof <br />1 <br />0.002 <br />0.002 <br />Apache <br />Coal <br />3 <br />0.15 to 0.80 <br />0.48 <br />Floor <br />2 <br />1.10 to 1.46 <br />1.28 <br />Roof <br />4 <br />0.001 to 0.04 <br />0.02 <br />Maxwell <br />Coal <br />5 <br />0.02 to 0.29 <br />0.013 <br />Floor <br />2 <br />0.04 to 0.10 <br />0.07 <br />Roof <br />2 <br />0.02 to 1.06 <br />0.54 <br />Blue <br />Coal <br />3 <br />0.12 to 0.47 <br />0.43 <br />Floor <br />3 <br />0.03 to 0.27 <br />0.11 <br />Coal <br />8 <br />0.02 to 2.45 <br />0.43 <br />Other units <br />Sandstone <br />3 <br />0.01 to 0.84 <br />0.31 <br />Siltstone, Mudstone and Shale <br />11 <br />0.001 too. I 1 <br />0.02 <br />4164A.110130 Whetstone Associates <br />PR 02 <br />Exhibit 8(4) Page 141 <br />Revised 1/31/11 <br />