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1 <br /> <br /> <br /> <br /> <br /> <br /> <br />i <br />1 <br /> <br /> <br />1 <br /> <br /> <br /> <br />t <br /> <br />1 <br /> <br />EXBIBIT D (Cont'd) <br />Mining Plan <br />Mining began in Stage I in early 1977 under permit number 77-20 <br />at the north end of affected lands. In the initial part of each <br />stage a portion of the stage is stripped and the overburden and <br />soil material is segregated and mounded in stockpiles until needed <br />for backfilling and resoiling. The setback perimeter is used for <br />stockpiling (see map D-1). As mining started, water was encountered <br />at about 4 feet. At first mining was carried on below the water <br />line by dragline. It was planned that as the depth of water <br />reached about 10 feet, dewatering would be started. It was hoped <br />that as the pit grew deeper, enough water could be removed that <br />the depth of water would not exceed 10 feet. In fact, dewatering <br />was much easier than expected. It was soon obvious that the pit <br />could be completely dewatered acid mined with front-end loaders in <br />dry conditions. <br />Pit 1 is now being mined by using two 10-foot high steps <br />(benches) to reach the deepest part of the pit at 30 feet. This <br />step runs nearly east-west across the pit. As mining continues <br />to the south, the 10-foot-high wall of each step will move to the <br />south. <br />As the north and east pit perimeter are cleared, backfilling <br />and resoiling from the mounded stockpiles. will be started. Those <br />areas where the slope is greater than 3 to 1 will be reshaped <br />so that slopes oP 3 to 1 will be maintained from elevations of <br />4958 feet to 4973 feet, approximately 10 feet below and 5 feet <br />above the permanent average water level of 4968 feet. <br />6 <br />1 <br />