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19u1' 29. 2001) <br />Toe of Dragline Spoil Pile <br />Coarse Dram Material Source <br />Silt Fence <br />(During Construction <br />of Drain) <br />Page 21 <br />Coarse Drain Material (12"-60")' <br />Recovered from Toe of Spoil Pile <br />7 1 'All Draim Material <10% <12" <br />Maximum 25% of Drain Width <br />16.0- " <br /><16.0 <br />5.5 <br />- 22.0 - <br />535-21 trapper Mining 1531-21.2 Rapper App-A Owg. Layout Fig-211 nn C/smv1 (55-29-20191 <br />Figure 24. Schematic Ura%Ning of Proposed Underdrain <br />The location of the underdrain in relation to the centerline of the spoil pile maximizes tile abliltv <br />to recover large durable material for core construction. The height of the pile should promote <br />good segregation to firm a natural filter system. <br />4.4 Construction Recommendations <br />The K-Pit Mine has been divided into 4 distinct areas. K-Ridge, A-Block, B-Block and <br />C-Block. The extents of these areas are shown in Figure 27. <br />The first mining activity in K-Pit is to strip the K-Ridge area using a draglinc. Mining <br />will progress from west to east, casting the spoils into I lorse Gulch. The projected extents of the <br />dragline spoils are shown in Figure 28. As mentioned in the underdrain design section this <br />material will drape over a section of the underdrain. The core of the underdrain is constructed <br />ahead of' the nlain spoil pile from large rucks retrieved from the toe of the main spoil area. A <br />schematic sketch of this construction process IS included in Appendix A. <br />When K-Ridge stripping is approximately halfway completed (about 5 months). the haul <br />truck fleet will begin stripping B-Block to the L-Sear. The spoils will be hauled around the <br />north end of the K-Ridge, establishing a dump bench at approximately the 7,500-ft elevation that <br />will slope to the West. This slope will allow surface runoff to flow off of the dump bench into <br />sediment traps. As stripping progresses down the hill, a portion ofthe B-Block spoils Will be <br />Agapito Associates. Inc.