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Received <br />JUL 12 1899 <br />EXHIBIT D: RECLAMATION PLAN <br />Durango Field off <br />l ion of Minerals g ce <br />(a) Overburden: The Yule Quarry is and underground operation. The seam of marble Geology <br />is 300 feet thick and is entirely exposed at the surface. No overburden removal or backfilling of <br />the underground excavations is anticipated. It is anticipated that the north and middle quarry <br />entries will be left open and unchanged from their current condition. The south quarry entry will <br />also remain open, but a new portal has been opened on the south wall of this entry. The quarry <br />portal driven by CYMC in 1990, the entry driven in the south wall of the south quarry entry, the <br />small utility tunnel and any new quarry entries will be backfiliged to prevent public access to <br />underground workings. <br />(b) Waste Pile Slopes: The effective overall <br />slope of the final surface of the waste piles is to 2:1 <br />(horizontal: vertical). This slope is lower than the <br />slopes of the existing waste piles that have proven to <br />be stable for the 49 years between 1941 and 1990 <br />when the quarry was inactive. Based on the data <br />provided by existing waste pile slopes, it is the writer's <br />opinion (Rex E. Loesby, Colorado P.E. No. 20338) <br />that new waste pile slopes will be stable if they are <br />established at angles less than existing waste pile <br />slopes. The new waste pile slopes will be consistent <br />with the existing natural topography and will blend <br />well in the mountain terrain. The photo at right, taken <br />in 1988, shows the upper waste pile left from pre -1941 <br />operations. Sierra will continually monitor existing <br />and new waste pile slopes. If significant unstable <br />conditions develop, corrective stabilization actions will <br />be taken, either by reducing the slopes or through <br />mechanical stabilization methods. As outlined in the <br />Mining Plan section above, Sierra plans to deposit new <br />waste to the piles so the final slope in these new areas <br />does not exceed 2:1. The contour maps on the <br />following page show the current contours of the waste <br />pile areas and an estimate for the maximum extent of <br />the waste piles post reclamation. The final contours <br />were estimated based on a maximum 2:1 final slope. <br />The volume created by the maximum extent of the <br />waste piles is estimated at 159,000 cubic yards. Assuming a density of 1.5 tons per cubic yard, <br />the waste pile's capacity is 240,000 short tons, well in excess of the total amount of waste to be <br />generated over the life of planned operation. Initially, waste blocks will be placed to the east and <br />south of the existing waste piles, being careful to not <br />Permit Number <br />Cass 9Perma TT', <br />Section /Exhibit: <br />Class: Revision <br />----------------------------------- _- <br />! Type /Seq: <br />Classy 0 Report 0 Hydro bd eral <br />Doc Type: 23 <br />- --n - -- -- ---------------- ----- - - -- ----------------- <br />DApplication (Coal only) ❑Bond ❑Enforcement ❑Inspection <br />