2011-06-29_PERMIT FILE - C1981019 (8)

Home Browse Search

The bond calculation is provided Volume 13, Exhibit 13A. Within these tables, truck haulage of spoil back to South Taylor pit backfill appears in Table 13 (pages Exh. 13A, T13 -1 and T13 -2). Reviewing the rows in Table 13, the relevant truck hauls that are affected by the revised "2012 worst case" topography are those that draw material from elevations at or above EL 8000 ft in the East Taylor temporary spoil. It can be observed in Table 13 that these hauls appear as the bottom three rows of that table. Because the haul distances and grades differ on these three haulages, there are three different direct costs, ranging from $0.93/CY to $1.39 /CY. The weighted average Direct Cost of these three hauls is $1.18/ CY. The net effect: of the additional 500 feet of ramp length and the 728 foot shortening of the distance to the center of the pit produces a small reduction of 228 feet in haul length for these lifts. This distance is then doubled to 456 feet for each round trip, resulting in the slightly decreased cycle times as presented in attached Table 1. Applying the same methodology, but decreasing the haul distance on each of these hauls by 456 LF, a slightly decreased direct cost of $1.13 /CY is obtained. The incremental direct cost reduction of $1.18 - $1.13 = $0.05 /CY must be applied, but only to the 10,100,000 CY affected by the revised spoil pile geometry as described above. Because the incremental cost change is such a small fraction of the total cost, it is reasonable to assume the indirect costs will not change. The appropriate decrease in bond amount is tabulated below. Original Direct Cost $53,514,931 Original Subtotal Indirect Costs $14,709,192 Original Grand Total $68,224,123 Direct Cost Reduction from TR -81 10,100,000 CY x - $0.05 /CY = -$505,000 Indirect Cost change from TR -81 Assumed no change $0 -$505,000 Revised Grand Total $67,719,123