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-z- <br />• degrees. The east wall has been excavated to a similar angle. The east <br />wall has been benched as required to maintain stability and provide haul <br />roads for the scrapers used in the mining operation. The coal beds being <br />mined strike in a general north-south direction and the mining operation is <br />progressing to the south. In the current operation, coal is excavated to <br />the surface of a relatively competent coal and the hard sandstone is left <br />exposed as the west wall. The overburden is stripped using scrapers. The <br />overburden materials are ripped with large caterpillar tractors but no <br />blasting is currently used exceot in the coal. <br />PROPOSED EXPANSION <br />We understand the relative economics of extending the depth of mining <br />to 400 feet is the primary reason for this study. The mine will be extended <br />approximately 4,000 feet to the south along the outcrop of the Suddeth coal <br />• bed. The depth of mining will be increased from the current 200-foot level <br />to approximately 400 feet. A map showing the general configuration of the <br />existing mine and the proposed area of expansion is shown on Fig. 1, the <br />Vicinity Map. Reserve studies are currently in progress to determine the <br />most favorable depth considering the amount of stripping and the estimated <br />coal. For purposes of this stability analysis, a maximum depth of 400 feet <br />vertically from the outcrop elevation was used. The pit will decrease in <br />depth at both the north and south ends of the proposed project. The west <br />wall of the pit will be excavated essentially parallel to the dip of the <br />bedding, which is approximately 45 degrees to the east. Safety benches at <br />each 120-foot level of pit depth are planned to control r•ockfall. The east <br />• <br />