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Mr . John Doerfer <br /> April 18 , 1991 <br /> Page 2 <br /> 3 . Erosion at natural - fill interface <br /> The area where the pile joins the hillside will be required <br /> as a haul road if Tailings Pond #1 is reclaimed by the same <br /> method proposed for Tailings Pond #2 and will be constructed <br /> for possible use as such for the short term. The flatter <br /> section of this area on top of the Pond will be about 50 <br /> feet wide. The width will taper to 20 or 30 feet on the <br /> eastern and western portions of the pile . The area will. not <br /> slope transversely and as such will provide a wide channel <br /> which will minimize flow velocity and erosion . Also, the <br /> area will slope away from the middle of the pond on both <br /> sides . This will reduce the contributing area thereby <br /> reducing the maximum flow in any given section of this <br /> channel . The anticipated road area (drainage channel ) will <br /> be constructed by sub-excavating the tails to a minimum <br /> depth of one foot . This material will be replaced by one <br /> foot of overburden compacted to 950 of its maximum dry <br /> density. This will provide a relatively impermeable runoff <br /> channel . Final reclamation of the area will consist of <br /> placing an additional foot of loose overburden on it. It <br /> will then be seeded zinc] covered with Jute or anotner <br /> suitable erosion control net where necessary to prevent <br /> erosion and ensure vegatative cover. Final reclamation will <br /> occur after usage of the area as a haul road is no longer <br /> anticipated. See attached map. <br /> 4 . Ceotechnical, study <br /> The Tailings Pond #2 Geotechnical report is included with <br /> this letter. <br /> 5. Lead Carbonate Tailings <br /> Included in the Technical Revision request was a plan to <br /> move the Lead Carbonate Tailings to Pond #1 . Currently <br /> there is no plan for the reclamation of the i,ead Carbonate <br /> Pond. Moving the tails to Pond #1 is believed to be the <br /> best approach because available overburden material is <br /> scarce in the area of the pond and Tailings Pond No. 1 will <br /> require material for reclamation (if the plan requires <br /> capping the top to prevent ponding of water) . Approximately <br /> 40 , 000 cy, of material will be required to fill the low spot <br /> at the west end of Tailings Pond #1 . The Lead Carbonate <br /> Tails will supply approximately 10 , 000 cy of the deficit. <br /> The Lead Carbonate Tails are expected to be similar to Ponds <br /> 1 , 2 , 3 and 4 since the origin of the material was from the <br /> same geographical and geological area . Two samples were <br /> obtained from the Lead Carbonate Pond and analyzed by CDS <br /> Laboratories . The results are attached <br />