2016-08-01_PERMIT FILE - C1981010A (7)

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1.4 DETERMINATION OF BOND Trapper Mining Inc. presently maintains a reclamation performance bond for the Trapper Mine payable to the State of Colorado and the United States Office of Surface Mining Reclamation and Enforcement. Upon approval of this permit application, a performance bond or equivalent, acceptable surety will be secured in an amount equal to the estimated costs for returning the affected area to a satisfactory condition as defined by applicable regulations and this permit application. The equipment productivity estimates used in regrade time calculations were derived from the Caterpillar Performance Handbook, edition 38. Topsoil fleet hours were derived using TALPAC haulage simulation software. DRMS database ownership and operating costs were used where available; otherwise, these costs were extracted from Trapper Mining Inc. historical data and information obtained from Wagner Equipment Rentals. All reclamation costs were calculated according to the worst-case condition of reclamation requirements. The costs that were calculated in this manner realistically represent those the Division could incur at any time during the permit period, and not just for the conditions that may exist at the end of the five years. Appendix A Tables A-1 through A-14 summarize regrade, topsoil replacement, revegetation areas & costs, demolition, and miscellaneous costs associated with mine closure. The driving factor in determining the worst case year was the extent to which K -pit has been opened. This is both a truck/loader and dragline pit. During the worst case year, which is estimated to be 2014, the depth and resulting volume of material required to backfill K pit is at its maximum, with respect to the permit term. Although the length of pit projected to be open is not as great as in 2013 (see Table 1.4-2), the depth, area, and resulting volume is larger than what is anticipated for years 2013, and 2015 through 2017. By mid -year 2014, both the down dip cut and the last strikeline cut in K pit are exposed. This occurs as the transition from the landslide strikeline pits to the down dip cuts of L and M pits takes place. At the time of this transition, the resulting open cuts will require approximately 2.8 million cubic yards of material to bring the final K pit to the projected post mining topography. AE (East Ashmore), and D (Derringer) pits remain unchanged for the permit term due mainly to mining operations being concentrated in K, L, & M pits. The Ash Pit will continue to be utilized for ash disposal, and G dip pit will be consumed in 2015 by L pit and substantially reducing the total exposed open cut length As L pit, then M pits advance eastward, a smaller area of remaining disturbance is realized as spoil grading is brought to concurrency with the dragline operations, as has been the case historically at the Trapper Mine. A summary of the estimated mine closure cost is presented in Table 1.4-1. Please refer to Map M 6 for the post mining topography for the worst case bond year (2014) and to subsequent tables and sections in Appendix A of the permit application as indicated in Table 1.4-1 for more detailed analysis and discussion. The bond amount of $20,291,400 will be applied to our permit revision (PR7). This represents the worst case cost for the period 2013-2017. Trapper estimates that during the worst case year of 2014, the total disturbance within the approved permit area will be 1,968 acres, which includes miscellaneous areas such as light use roads and silo locations. The reduction in the bond amount is due mainly to the reclamation of F pit and the decreasing areas of remaining disturbance as the mining operation approaches the existing permit boundary. 1-31 --i\ 10 13,