1980-10-20_REVISION - M1977493 - Laserfiche WebLink

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6. Q. Are any of the old drifts and stopes being filled with waste rock; if not, why? A. Old underground stopes and drifts are not backfilled . A modified block caving method of mining is used underground at Climax , so the old stopes and drifts are effectively eliminated by the mining process itself. 7 . Q. Why are the Robinson and Tenmile Tailing ponds kept active for so long? A. The permit amendments do not propose any change in the size , location or method of operating the tailing ponds. The Robinson and Tenmile tailing ponds are being kept active for the following reasons : 1. Water pools within the tailing ponds are used as part of Climax' process contact water management system. This system will remain active during the life of the mill . 2. Alternative systems for tailing delivery and deposition are required as part of any normal and safely-operated tailing depo- sition program. At present, the Robinson and Tenmile ponds serve as alternative systems to the Mayflower tailing pond. As part of our normal operating procedure , tailing deposition is rotated from section to section on tailing pond crests. This is done to control the phreatic line . During routine maintenance on any one pond ( such as raising the crest) , tailing deposition must be rotated to another pond . 8. Q. Has any topsoil from the Mayflower tailing area been used for reclamation; if so , where and how much? A. Approximately 250 cubic yards of topsoil from the Mayflower tailing area was used for land- scaping at the Water Treatment Plant, and 5000 cubic yards were provided to the Colorado Department of Highways for revegetation of cut and fill slopes along the new section of Highway 91 . Approximately 30 , 000 cubic yards of topsoil -3-