2004-06-11_REVISION - M1986061 - Laserfiche WebLink

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South Pit Natural Fine Produced from each Area ea Total Tons Waste Tons@36 % reject Waste cy(lcy =1.5 t 1 480,634 172,991 115,32 540,713 194,615 129,7 609,693 219,443 146,29 448,740 161,512 107,67 373,085 134,282 89,521 outh Pit Fill -28,78 alley Fill #I -89,84 opsoil Blending(SP) -13,811 opsoil Blending(VF) -17,00 alley Fill #2 -110,68 lope Backfilling or Addi- -328,44 'onal Subsoil otal If the entire excess natural fines aze used as subsoil throughout the flat portion of the South pit and the staging area, this would provide an additional 5' of subsoil. An alternative use use is to reduce the cut slope to a grade milder than 2H:1 V. Valley Fills The natural drainages passing through the pit will be filled using excess fines or overburden. This will require approximately 210,000 cyto fill Valley #1 and an additional 110,000 cy for Valley #2. A letter has been obtained from the Army Corps of Engineers in Durango stating that these valleys do not contain any wetlands or jurisdictional waters of the United States. Only reject fines or overburden will be used to provide a homogeneous fill for stability reasons. Fill will be spread in 12" lifts along the bottom of the drainage. Using shallow lifts, a 90% maximum dry density will be achieved and is specified for this fill. The spreading will be done with a D-8 Dozer equivalent or larger. To prevent sediment from leaving the permit azea during construction ofthe valley fill, and prior to the installation of the storm water channel, an isolation berm will be constructed at the mouth of the drainage as seen in Map 3. After the valley has been filled, the area will be topsoiled in a similaz fashion as the Staging Area. This will be further discussed in the Reclamation Plan. 7. Water Information, Rights and Augmentation The operation is planned to be a dry operation and no water will be used during the actual mining operation. The only water needs for operation will be for dust mitigation in the processing plants and on roads. This water will be supplied by wells on the Cugnini property supplying a portable water tank that will be located on the site. Cugnini has the water rights to supply this tank. If groundwater is exposed during mining, the owner will either proceed to obtain the proper water rights throuhg a gravel well permit or will immediately backfill any groundwater exposure. The water table level fluctuates with the seasons with the average depth of the water table being unknown. The lowest point would be during the months of February, March, April and May and the high point being during summer months. The maximum rise appears to follow spring runoff and the Cugnini 12{03 12