2023-04-19_PERMIT FILE - C1981010A (38)

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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 49. 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 Ithaca (I), Jennings (J), Colt (C), Lancaster (L), and Nighthawk (N)- pits have been opened. During the proposed worst-case year, which is estimated to be 2023, the depth and resulting volume of material required to backfill C, I, J, N, and L pits is at its maximum, with respect to the permit term. The projected new disturbance, which includes the dragline, dozer stripping, and truck/Excavator operations, is greatest in the year 2023 (see Table 1.4-2). The primary contributing factor to the increase in the projected Performance Bond for the worst-case bond year of 2023 is the development of C, I, and J Pits. These pits will be opened in 2022, with topsoil stripping operations and development of the initial box cuts. By 2023, N pit will have advanced to the point that much of the box-cut is open, with some additional pre-stripping having occurred, thus resulting in a substantial area of pit being open. In addition, highwall mining in the initial boxcut is in progress, which will require a delay in reclamation activity during this process. The Ash Pit is anticipated to still be receiving ash from Craig Station. There will be some reclamation done in the ash pit by 2023, but a significant portion of the pit will remain open beyond the permit term. Derringer/Enfield Pit, previously anticipated to receive ash, will be partially graded in 2022, but will not be Phase I bond released, and therefore will be included back into the PR11 Bond Estimate. As L pit advances eastward, the cuts tie into the former East A (AE) pit. AE pit has been incorporated into L pit and, therefore, will be no longer be referred to as a separate pit. Due to the pre-stripping operations with the Truck/Excavator fleet, combined with the dozer stripping and dragline operations, L pit’s overall disturbance area, with respect to the five year permit term, is greatest in 2023 (see Table 1.4-2 ). 1-31