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303-279-8532 <br />303-279-1609 Fax <br />eeeoxcar@att.net <br />TECHNICAL MEMORANDUM <br />To: Anne Beierle and Tony Lucero, Henderson Mine <br />From: Mike Ellis <br />Date: September 11, 2002 <br />Subject: Henderson Tailing Pond Growth Media Replacement Cost Estimate <br />You asked that I submit the cost estimates as I finished with them to facilitate your <br />responses to DMG. The f fdi one I have completed is the cost estimate for growth media <br />replacement on the tailing pond and dam area, which is attached for your perusal. For <br />purposes of a realistic cost estimate, I took the topsoil stockpile locations and volumes <br />provided by Erich Bower in our onsite meeting of August 27, 2002 and developed a soil <br />replacemenl plan that optimizes haul distances using existing roads where possible. <br />Having physically "mapped out" the haul roads and measured the soil replacement <br />blocks, I was able to compute weighted average haul distances rather than simply <br />estimafing the distances. In my back-up sheets please f nd the soil replacement plan map, <br />the table of block volumes, azeas, haul distances, and weighted average haul distances. <br />Additionally, I looked at two scenarios-scraper hauled soil and truck hauled soil. <br />Scraper hauled growth media for all blocks comes out to be $2,194,726 (for 1011 acres of <br />tailing) compazed to DMG's estimate of $3,046,251 (for 1011 acres of tailing). My <br />analysis of truck hauled soil is the more expensive option and therefore I have eliminated <br />it. <br />DMG chose to use scrapers for part of the hauling and trucks for the rest. Their analysis <br />did not account for a dozer in the "cut or borrow area" to loosen up the soil before <br />loading, which in my opinion is a necessity. Similazly, DMG's cost estimate uses a D9 <br />dozer in the "fill" azea to spread soil (in my opinion this is the wrong machine). I believe <br />a D6 dozer (low ground pressure model) is absolutely necessary to spread soil in soft <br />tailing. Therefore, in my analyses I use a "push" dozer in the "cut or borrow areas" for <br />assisting with soil loading, and a D6 LGP dozer in the "fill" azeas to more appropriately <br />reflect real-life conditions. <br />My back-up sheets are attached. Call me if you have any questions. <br />Attachments <br />Ellis Environmental Engineering, Iuc. <br />4342 Ulysses Way <br />Golden, Colorado 80403 <br />