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J. E. STOVER 8 ASSOCIATES <br />2768 COMPASS DRIVE, SUITE 101 <br />GRAND JUNCTION, COLORADO 81506 <br />PHONE: (970) 245101, FAX 242-7908 <br />MINE ENGINEERING <br />MINE RECUMATION <br />June 10, 1998 <br />III IIIIIIIIIIIII III <br />CML ENGINEERING <br />CONST. MANAGEMENT <br />RECEIVED <br />J. J. Dudash <br />Division of Minerals ~ Geology <br />1313 Sherman St., Room 215 <br />Denver, CO 80203 <br />JUN 12 1998 <br />Division of Minerals ~ Geology <br />Re: Bowie No. 2 Mine <br />Cut Slope Slide <br />Permit C-96-083 <br />Dear Mr. Dudash: <br />The DMG's letter dated April 14, 1998, requested additional informed regarding the <br />referenced slide. <br />Enclosed is a drawing which presents a plan and section view of the small slide area. <br />The cross section view shows the pre-slide slope, the existing slope and the proposed <br />repaired slide slope. It is estimated the slide mass encompassed 5,000 cubic yards. <br />The pre-slide slope grade was 1.5h:1v or flatter. <br />The DMG requests details of the proposed remediation plan along with information that <br />would document that this plan will result in a stable repaired slope. The remediation <br />plan is presented on the enclosed drawing. The final slope surface will not be quite as <br />steep as the slope that failed. <br />The DMG further requests a slope stability analysis using information from the Maxim <br />geotechnical reports and a discussion of why the slope failed in the first place and why <br />the proposed repair plan will not result in further slope failure. <br />The original Maxim geotechnical report dated July 10, 1996, page 13, states in part, <br />"Permanent cut slopes should be no steeper that 2:1 (horizontal to vertical) overall, <br />including benches. Although, for areas where the owner can accept an increased risk <br />of shallow slope failures, .... ,cut slopes can be as steep as 1.5:1 (overall) where <br />located well above ground water levels in the very stiff to hard clay. <br />