Laserfiche WebLink
can be accomplished using the mine scales and the known volume of a front end <br /> loader bucket. This information can then be used in establishing the bond <br /> estimate. In addition to the physical properties, a chemical analysis of[he topsoil <br /> must be performed to determine the quantity of fertilizer that will be needed to <br /> assure successful growth of vegetation during final reclamation. <br /> Five Year Waste Pile <br /> A revised estimate of 500o cubic yards of waste rock production annually was <br /> used in estimating the elevation of the 5-year waste pile. Beginning with the <br /> existing waste rock volume, approximately 25,000 cubic yards, and adding the <br /> annual increment, results in a required 5-year volume of 50,000 cubic yards. This <br /> corresponds to a pile height of 75 feet (elevation 7490). The boundary of the 5- <br /> year pile is shown on the accompanying design drawing. In addition, the volume <br /> of cover material (fill and topsoil) for the 5-year pile was estimated at 7000 cubic <br /> yards. Of this, the mina operator estimated chat they currently have enough cover <br /> stockpiled to accommodate the existing pile (about 4800 cubic yards of cover). A <br /> location for the 5-year cover storage pile (7000 cubic yards) is shown on the plan <br /> drawing. <br /> drainage Features <br /> Enlargement of the waste pile will require modification of the drainage <br /> intercept ditches on both the north and south side of the pile. In addition the - <br /> sedimentation ponds will be altered to accommodate the increased contaminated <br /> runoff volumes. All ditches and pipes are sized for the 200 year event and the <br /> ponds for the �O year event. Please refer to the drainage report (revised July <br /> t997), and the accompanying design drawings for details. <br /> The Eastside drainage channel will be moved from its existing location, to the <br /> north against the natural hill slope. As the waste bank increases in elevation the <br /> ditch will move up the hillside. Ai the top of the sloping pile faced the channel will <br /> intersect an armored channel that will flow down the front face of the waste pile. <br /> These two ditches will route uncontaminated water to the clear water tliversion <br /> system. <br /> A similar set of intercept ditches on the south side of the pile will collect <br /> contaminated runoff from the pile and some clear water from the adjacent hillside <br /> and route it to the sedimentation ponds. Please refer to the design drawings and <br /> the drainage report for details. <br /> Underdrain <br /> An untlerdrein system for the waste pile is required by the regulations. The <br /> purpose is to intercept water which originates either forth precipitation infiltration <br /> through the waste pile surface or from the interception of groundwater at the pile- <br /> January 1998 <br />