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- 3 - <br /> Reclamation Plan Issues <br /> The mine consists of many separate areas, each of which presents a different <br /> reclamation situation. The tailings impoundments involve the most challenging <br /> reclamation problems. We recognize that any reclamation plan must incorporate <br /> some degree of flexibility; however, reclamation is no longer a future problem <br /> so specific reclamation plans must be initiated. The amended reclamation plan <br /> should include plans to provide characterization of the existing disturbance <br /> (as previously discussed), a preliminary reclamation plan, and then a detailed <br /> monitoring plan that will be implemented to evaluate reclamation progress and <br /> that will be used to assess any necessary changes. <br /> Tailing Impoundments <br /> These facilities include the Robinson, Ten Mile and Mayflower Tailing <br /> Impoundments, the Old Tailings Pond (if not already covered) , the Oxide <br /> Tailings Pond and any other minor tailings facilities not shown in the <br /> existing plans. The main issues involve long term geomorphic stability, <br /> hydrologic balance issues, revegetation issues and, ultimately, achievement of <br /> a beneficial end-land use. <br /> 1 . It will be important that any permanent upland drainage diversion <br /> systems function without maintenance, unless the reclaimed tailings <br /> ponds are stabilized against erosion or incision resulting from <br /> uncontrolled runoff originating at upland locations. The existing <br /> plan involves buried diversion lines, gabian structures used to hold <br /> hillslopes above canals and general tailing surface grading to <br /> accommodate this problem. These solution will work in the short <br /> term; however, they do not seem to provide long term stabilization. <br /> For example, the gabians will eventually fail , possibly causing flow <br /> obstruction in the underlying canals, which may lead to canal <br /> overflow and erosion of the tailings. <br /> Please discuss long term surface runoff management and erosion <br /> control plans that are designed to protect the reclaimed tailings <br /> impoundments against erosion and subsequent off-site tailings <br /> transport. Such plans should emphasize maintenance-free <br /> stabilization. <br /> More design details should be incorporated into the permit document. <br /> This information should include a map which portrays the location of <br /> all flood control reservoirs, interceptor ditches and canals, dam <br /> spillways, etc. Additionally, the plans should contain typical ditch <br /> sizing criteria so that the information can be verified in the <br /> field. Gabians located above ditches and the location of ditches <br /> below steep cut slopes indicates a probability that intensive <br /> diversion maintenance is required. Discuss your specific flood <br /> control and diversion system maintenance scheme. <br />