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The fill area will be properly prepared and constructed as detailed in Agapito Associates, Inc.'s "Horse <br />Gulch Fill Stability Analysis." This geotechnical investigation report can be found in Appendix T, and is <br />dated May 2009. <br />The fill is constructed via dragline spoil from the K Ridge Pit, and T/E spoil. The dragline portion will be <br />constructed first through normal dragline spoiling. The T/E portion of the fill will be constructed in lifts <br />from the floor of Horse Gulch. Lifts will not exceed 100 vertical feet, and will typically be 25 to 50 vertical <br />feet. In general, these lifts will be placed from the outside toward the center. A suitable berm will be <br />constructed at dump points, allowing end dumps to back up to the edge of the fill, and dump. As <br />conditions require, and more likely with increased lift height, trucks may dump short of the berm, and use <br />of a dozer to push the material to the lift edge will be required. <br />The West face of the fill will have an overall slope not to exceed 3H:1 V. A 30 foot horizontal bench will be <br />constructed every 100 vertical feet. This will promote drainage of runoff at velocities low enough to <br />prevent cutting the face of the fill. Additionally, this will reduce the overall slope of the face to less than <br />3HAV. The final bench will be constructed at the 7570' level, and slopes at this point will reduce to <br />4HAV, or less. Lifts will be placed to a maximum elevation of about 7740' and will tie into the existing <br />ridgeline. The profile of this head of hollow fill will slope downward from this point, and will remain lower <br />than the existing ridgeline. <br />Drainage is an important consideration in the design of this head of hollow fill. An underdrain will be <br />constructed as specified in AAI's "Horse Gulch Fill Stability Analysis" (Appendix T) to promote drainage <br />from within the fill. Surface water diversions are depicted in Figure T -1, Appendix T. <br />Lifts will be constructed to promote drainage, and reduce the ability of water to stand on the surface. This <br />will reduce the amount of infiltration into the fill. Where appropriate, best available construction practices <br />will be used to prevent fine material from entering the underdrain. <br />This head of hollow fill will be left as a permanent feature because it is an excess spoil fill. As such, the <br />fill will be retopsoiled, and planted in permanent vegetation compatible with the planned post mining land <br />use of Rangeland and Wildlife Habitat. <br />3-40a <br />7R 16(0 <br />51142DIO <br />