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<br />DIVISION OF MINERALS AND GEOLOGY <br />DepaMlent of Natural Resources <br />1313 Sherman gt., Room 21 S <br />Denver, Colorado 80203 <br />Plrone; (303) 866-3567 <br />FAX: (303) 832-8106 <br />October 2, 2002 <br />Anne Beierle <br />Climax Molybdenum Company <br />P.O. Box 68 <br />Empire, CO 80438 <br />RE: Climax Molybdenum Company; Henderson Mine & Mill; Permit No. M-1977-342 <br />Techuical Revision No. 12; Adequacy Letter <br />Dear Ms. Beierle, <br />DIVISION OF <br />MINERALS <br />GEOLOGY <br />RECLAMATION <br />MINING-SAFETY <br />BIII Otvens <br />Goverrwr <br />Greg E. Walther <br />Executive Director <br />Ronald W. Canany <br />Acing Division Director <br />On September 6, 2002, the Division of Minerals and Geology received Climax Molybdenum's Henderson <br />Mine/Mill (Henderson) request for a Technical Revision (TR-12) to the mining and teclatnation permit TR-12 <br />was filed to reduce the amount of financial warranty required based on the Division's cost estimate that was <br />provided to Henderson on July 9, 2002. The Division has the following comments regazding the Technical <br />Revision. <br />1. 3.1 ReduMion of Buffer Area Disturbance: The operator proposes to reduce the buffer area disturbance <br />from 393 acres to 75 acres. Henderson does not wish to eliminate any of the 393 buffer acres from the <br />affected azea within the Peanit boundary, but proposes to reduce the total Financial warranty for the buffer <br />area to account for only 75 acres. The Division accepts this reduction with the condition as stated in the <br />Technical Revision app&cadon that the Financial Warranty will be supplemented as approved by the <br />Division prior to disturbance in the remaining 318 buffer acres. The Division should be contacted at least <br />30~ays prior to anticipated disturbance in the 318 acre buffer atra in order to facilitate the necessary <br />increases in the Financial Warranty amount. <br />2. 3.2 Structural Demolition- On Site Disposal: Henderson proposes to revise the permit to allow onsite <br />disposal of swctura( rateral that cannot be salvaged. The Division approves this change in disposal <br />method, and [he various locations proposed by [he operator. However, Henderson will need to estimate the <br />amount of material that cannot be considered adequate to dispose on site (i.e. material that would not meet <br />the definition of "inert material" as defined by Rule 1.1{24) of the Hard Rock/Metal Mining Rules & <br />Regulations). Such material will need to be hauled to a designated Iandfill. Please note that while <br />swctural steel, concrete, and asphalt are considered to be inert, wood and wood products are not: <br />Henderson may provide an inventory of such material, or assume a certain percentage of any particular <br />stmcture. <br />3. 3.2.1 Disposal Locations: Please specify the cover depth to be placed over the swctural material disposal <br />sites (the Division recommends 3-feet minimum), the borrow location and volume of material to be used as <br />cover, and the approximate reclaimed slopes of the disposal sites. <br />4. 3.2.2 Material Testing and Burial: Henderson proposes two disposal sites at the mill. The burial sites <br />are located to protect surface and groundwater, and Henderson states that disposal site preparation will <br />include construction of sides and bottom using relatively impermeable materials and geo[extile wrap or <br />some other suitable technology to protect free draining aggregates that will be required to collect and drain <br />leachate. Similaz design elements were required at the Climax Mine Storke Yard debris repository and <br />significant costs for repository preparation were incurred. An estimated cost associated with initial <br />repository preparation will need to be included in [he Financial Warranty amount. This will include a cost <br /> <br />STATE OF COLORADO <br />