2005-10-27_REVISION - M1977342 - Laserfiche WebLink

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STATE OF COLORADO DIVISION OP MINERALS AND GEOLOGY f/ Department of Natural Resources 7 313 Sherman St., Room 215 C O L O RA D O Denver, Colorado 80203 D I v t 5 I o N o f Phone: (303) 8663567 MINERAL S FAX: (303) 832-6106 / G E O L O G Y SL ~ ~z . / 0.E<LANATION•N ININC C/ VV YAFETY•YCIENCE Bill Owens DATE: October 27, 2005 Governor Russell George TO 1977 342' Fil N M Executive Diretlor : e - - o. ~ Ronald W. Cattany / `; Division Diregor FROM: ~ Allen Sorenson t~ Natural Resource Trustee / RE: Backing Documents for Reclamation Cost Estimate, Climax Molybdenum Company, Henderson Mine and Mil[ Enclosed with this memo are six documents that were used by DMG to make certain determinations relative to the establishment of the required bond amount for the Henderson Mine and Mill. DMG decided to accept the cost estimate provided by Henderson for the demolition of the snow shed that protects a portion of the ore conveyor from damages that might be caused by avalanches. The Henderson estimate of this cost is contained in the attached exhibits to their letter and report on operational and general clarifications dated September 20, 2002. Two of the documents that DMG relied on in making the determination to accept Henderson's estimate for this task are: 1.1. A demolition cost worksheet estimating the cost for nxbblization using explosives of the snow shed concrete roof slab at a direct cost of $57,850.51, which compares favorably with Henderson's estimated cost of $55,358.38. The estimated cost for rubblization using explosives contained on the worksheet enclosed with this memo significantly overestimates the cost because the unit cost input was derived for foot-and-a-half thick slab on grade concrete, whereas the snow shed roof slab is freestanding and is only eight inches thick. Therefore, the DMG has determined that even though the explosive rubblization estimated cost is slightly higher than the Henderson estimated cost, and that the Henderson estimated cost includes the post-rubblization tasks of grading, compacting, and covering the demolished snow shed, the Henderson estimated cost is sufficient to complete the job, if the hourly equipment costs input to the Henderson estimate are sufficient. 1.2. The Henderson estimate is based on two CAT 225 excavators working in tandem to demolish and reclaim the snow shed. Since CAT no longer manufactures the 225 excavator, a cost and performance data worksheet was prepared for the next generation excavator, the CAT 325C L. This cost and performance data worksheet is enclosed with this memo and it shows that the hourly equipment costs input by Henderson are more than sufficient. Adding to the conservatism of the Henderson estimate, and further justifying the DMG's determination to accept the Henderson estimate, is the fact that the 325 series excavators are more powerful and more efficient than the older 225s, and yet cost less per hour to own and operate. 2. DMG decided to accept the cost estimated by Henderson for the application of geotextile to stabilize soft tailing prior to capping. The Henderson estimate of this cost is contained in the attached exhibits to their letter and report on operational and general clarifications dated September 20, 2002. Office of Office of Colorado Mined Land Reclamation Active and Inactive Mines Geological Survey