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• Inspection of Dams and Sediment Removal <br />The sediment dams and embankmerns will be rou[iney inspected and mairnained during the life of the <br />Trapper Mine. Quarterty inspection records will be kept on file at Trapper for Division review. Coyote <br />Dam will be inspected by a certified dam inspector for the criteria of the Stale Engineer. The remainder <br />of the sedimern dams will be inspected by Trapper Mine personnel. The emergency spilhvays and prin- <br />cipal spillway outlets will be maintained to protect against erosion. Vegetative growth will be cut when <br />necessary to facilitate inspections and repairs. A quarterly report will be filed with the Division within 30 <br />days of the end of the quarter, illustrating the condition of each sediment pond. If necessary, an annual <br />report may be submitted to the Division by June 30th, after spring runoff. The report will designate which <br />impoundments require sediment removal and/or other maintenance. <br />Each sediment dam, except Coyote, will have the elevation showing 60°,6 of the designed sediment stor- <br />age capacity marked on either the principle spillway standpipe or on a staff gauge located near the spill- <br />way. The sedimern accumulated in Coyote Dam will be determined by probing each spring following <br />spring runoff. This is necessary because the dam is large and always has water in it, making it impossi- <br />ble to place or observe a mark at the desired level. Sedimern will be removed between late spring and <br />early fall only when ground conditions allow equipment access. All sediment control systems, except <br />Coyote, with 60°,6 or more of the sediment storage volume used following spring runoff will have the <br />sediment removed in the same year. Due to its large sediment storage capacity, Coyote however will <br />• require sediment removal in the same year when the available runoff storage to the principal spillway is <br />less than the in-flow volume attributed to a 10-year, 24-hour storm plus two years of anticipated sedimern <br />deposition from the Coyote drainage area as calculated from the Universal Soil Loss Equation using cur- <br />rent values. The material will be disposed in appropriate areas of the mine workings or used as a sub- <br />soil. Dams collecting runoff from the mining area contain sediment suitable to use as a subsoil. <br />Sediment Pond Removal <br />The sediment ponds will remain in operation until revegetation of the disturbed area is complete and <br />acceptable water quality is achieved. Written approval will then be requested from the Division prior to <br />removal of any of the sediment ponds. The affected area at the sediment pond will be regraded, <br />topsoited and revegetated upon removal. <br />• PR-3 <br />4-197 ,-- ------- -, <br />~?EVISION P py~ ~ i <br />~ DATE _-___~J__L--- ~ . <br />,I <br />I -- - <br />