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~oii iiiiii~iiiiiiiii • <br />® CLIMAX( MOLYBDEIVu)vl ~~ ~~~ ~, ~ ,' <br />A Subsitliary of Phelps Oatlge Corporation <br />August 28, 2001 <br />DMG -- CertiTied Mail No. 7000 0600 0026 1573 5844 <br />Mr. Bruce Humphries <br />Colorado Division of Minerals and Geology <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br />HENDERSON OPERATIONS <br />'19302 County Road 3 <br />Parshall, Colorado 80468 <br />(303) 569-3221 <br />Fax [97017250038 <br />t?ecup-f- / 0 7Q <br />~b75, cx~ <br />i K- <br />SEP 0 tl 241 <br />Division of Minerals and Geology <br />RE: Topsoil Salvage Methods -Technical Revision TR-l l Submittal, Henderson Mill, Permit <br />No. M-77-342 <br />1Jear Mr. Humphries: <br />Climax Molybdenum Company (CMC) would like to propose an alternative method to salvage <br />and stockpile topsoil. Historically, topsoil has been salvaged utilizing a conventional shovel and <br />truck hauling method. Instead, CMC would like to doze and windrow topsoil around our [ailing <br />impoundment. Although the topsoil will eventually have to be picked up and moved above the <br />ultimate tailing deposition line, this method allows CMC to salvage the most desirable soil (the <br />top 3 feet) from a greater area. Since other existing topsoil stockpiles will also need to be moved <br />from below the current interceptor ditch, this method also allows us to take advantage of [he <br />economies of scale when we move topsoil [o its final location <br />CMC received verbal authorization from Mr. Sorenson [o try this technique in a 2,000-foot test <br />area on the northwest end of the tailing pond. The test area was surveyed so that we would have <br />a baseline to measure the results against. We proceeded with the test utilizing our older D-9 and <br />D-8 bulldozers. Upon completion of the experimental method in the test area, CMC surveyed <br />the test area and found that our bulldozers were only capable of moving topsoil to an average <br />depth of 1.2 feet. This was not acceptable, as approximately 3 feet of soil recovery is necessary <br />to meet our reclamation requirements. CMC proceeded by renting a D-10 bulldozer to re-push <br />[he test area with a newer, more powerful piece of equipment. This bulldozer proved to be <br />effective. The test area was aeain surveyed on August 28`h and an average soil cut depth of 3 <br />fee[ was achieved. Based on the results of this test area, we would like to use this method on a <br />larger scale. <br />CMC will continue to push topsoil around the tailing impoundment until the onset of winter <br />weather forces us to stop. The windrowed topsoil stockpiles will be graded to approximately a <br />3:1 slope and broadcast seeded for interim stabilization as required. Tlie stockpiles will be <br />marked with signs and surveyed to verify volumes. Stockpile volumes and a map with locations <br />will be submitted with our annual report. <br />Based on the fact that this method will salvage greater quantities of the most desirable topsoil, <br />CMC respectfully requests that the DMG approve this technical revision. A check in the amount <br />of $875 is attached to cover the required application fee. <br />