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.~ ~% CLIMAX MOLYBAAD~~E~~NA/UMv~COMPANY A DIVISION OF I1I~^A/~ INC. FIENDERSON MINE Box 68 Empire, Colorado 60438 (303) 569-3221 March 6, 1991 Certified Mail No. P 582 492 925 Mr. Hruce Humphries, Mineral Chief Colorado Mined Land Reclamation Division 1313 Sherman Street, Room 215 Denver, Colorado 80203 RE: Technical Revision to Henderson Mine Permit Ho. M-77342 Dear Mr. Humphries: The lack of resolution of the Henderson Mine and Mill request in 1988 to reduce the required "Topsoil Replacement Requirements" to an average depth of six inches has caused soil stockpiling requirements and scheduling to be revised. As noted in the May 4, 1988 letter from Mr. Edward L. Bischoff of MLRD to Mr. Charles Jackson of the Henderson Mine, "The requirement to salvage enough material to replace 6-18 inches, or a 12-inch average, depth of soils remains a condition of your permit until we've resolved the item noted above, 'Topsoil Replacement Requirements'." The soil stockpile schedule as noted in Table 1 of the April 4, 1988 Technical Revision was based on the proposed six inch soil cover. This, coupled with changes in the production rate, have necessitated this Technical Revision. Production rates have increased at the Henderson Mine and Mill since the 1988 Technical Revision was submitted. However, molybdenum demand has remained relatively soft and the market continues to remain in an oversupply situation. Due to the nature of the deposit and the aggressive cost control measures that were instituted in the mid 1980's, Henderson has maintained its position as the industry leader through the most competitive period in history. The Climax Molybdenum Company is determined to remain the leader in the molybdenum industry and to that end the Henderson will respond to market conditions and continue to adjust production rates as necessary. Tailing basin preparation, perimeter access road and interceptor ditch construction and revegetation have been completed as per the schedule noted in the 1988 Technical Revision. Re-evaluations of in- situ soils available, projected annual pool elevations, total disturbed acreage by year at the anticipated production rates, logistics and operating plans have been completed. The operating plan that has been developed is based on the requirement that at any point in time soil stockpile inventory combined with in-situ inventory (soil in place in the prepared tailing basin) be adequate to cover the tailing deposition area with an average twelve inch soil depth. The current soil stockpiling schedule, based on the present production rate and projected mine life is shown by Table 1 and represented graphically by Figure 1. If production rates change to meet fluctuations in market conditions the soil stockpiling schedule will