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(e) Waste Piles, Mine Openings, & Other Features: With the exception of drainage <br /> features, all of these items are covered in previous sections. Once mining is complete, drainage <br /> from the quarry will commence when water has filled the existing workings up to the lowest <br /> possible exit elevation. This is anticipated to be the tunnel driven by CYMC in 1990. Water <br /> from this source will flow along the existing ditch along the portal access road a distance of <br /> approximately 700 feet where it will be allowed to percolate into the soils in the area known as <br /> Quarry Town. A 6-inch drainage pipe will be placed in the tunnel before it is backfifled so that <br /> water will drain and not allow a buildup of pressure behind the backfill in the tunnel. The pipe <br /> will be placed with a slight down slope to the surface so that ice will not form in the pipe to <br /> block it. <br /> A waste pile stabilization structure and a permanent sediment control structure will be <br /> built at the toe of the marble waste pile. The waste pile stabilization structure will involve the <br /> construction of a retaining wall constructed of the marble blocks from the existing waste pile. <br /> The blocks will be placed to create a stable retaining wall. The wall shall be off sufficient height <br /> and stability so that any movement of waste blocks from above will be stopped at the wall. The <br /> wall itself shall be built so as to provide some sediment control, but an additional permanent <br /> sediment control structure will be built below and to the north of the retaining wall. Depending <br /> on the results of the Division's determination concerning CYMC's potential off-site damage and <br /> resolution of certain property boundary and public access issues, Sierra may construct the waste <br /> pile stabilization structure soon after resolution of these issues. This would allow a safer traverse <br /> along the access trail where it comes near the toe of the waste pile. <br /> (t) Reclamation Costs: Reclamation activities anticipated include backfilling smaller <br /> quarry entries, fencing of larger quarry entries, construction of the waste pile retaining wall and <br /> permanent sedimentation control structure, and revegetation of approximately 1/3 acre of surface <br /> area. The table below presents a cost estimate of such work based on the assumption that an <br /> independent contractor is hired to complete the work. <br /> Item Estimated Cost <br /> Backfill Portals (1) $ 1,600 <br /> Waste Pile Retaining Wall & Sediment Control (2) 7,000 <br /> Entry Fencing (3) 6,000 <br /> Sub-soil Preperation (4) 640 <br /> Topsoil Hauling (5) 6,750 <br /> Topsoil Spreading (6) 640 <br /> Grass Seeding & Mulching (7) 350 <br /> Tree and Shrub Planting (8) 1,650 <br /> Total Estimated Reclamation Cost S24,630 <br /> (1) Assume two portals, each 16 feet by 16 feet. Assume 300 yards of waste rock for each, for a total of 600 yards. <br /> Assume eight hours of earthwork using a large wheel loader at a rate of$200 per hour including labor, consumables, <br /> and mobilization. Waste material is readily available from existing waste piles close to entries. A 6 inch drainage <br /> 22 <br />