2018-01-02_PERMIT FILE - C1980004A

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2.05.4 Reclamation Plan contours, place topsoil on the regraded area and seeding the area with the approved seed mix. (2)(b) A detailed estimate of the cost of reclamation of the proposed mine and mine facilities are presented in Table 3.7-1. (2)(c) The coal mine waste pile will not be reclaimed to approximate original contours. It will be contemporaneously reclaimed to the extent practicable. A general discussion of road reclamation is presented in Section 2.05.3(3)(c). Reclaimed areas will be compacted to at least 95% of the maximum dry density attained in a laboratory compaction test in accordance with ASTM D698 with moisture content +/-2% of optimum. The sandstone outcrop above the portals is a natural rock outcrop and was not a result of excavation. The average slope in the disturbed area will approximate original contours. The existing cut slope on the south side of the mine bench will be cut back. Material from the upper portions of the cut will be compacted along the toe of the slope to form a buttress. Figure 3.1.4 shows the existing cut slope as well as the slope proposed for reclamation. The location of this section (labeled CC) is shown in Figure 3.1-1. Stability analyses were run for both the existing and proposed configurations. Since no site specific information was available for soil strength parameters, results from Munger Canyon tests were used. These numbers are as follows: Friction Angle = 15 Degrees Cohesion = 1300 PSF Density = 130 Ib/cubic foot The analysis for the existing cut slope shows a safety factor of 1.234. This correlates well with the history of this slope as it has been stable with only very minor surface sloughing. An analysis of the proposed configuration (reclamation) shows an increase in the safety factor to 1.311. It should be emphasized that these safety factors are not absolute, but do show that the existing slope, which has been stable, will be improved upon reclamation. PR -02 2.05-38- 10/12