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Rule 6.4.4 Exhibit D- Minin¢ Plan <br />6. Please state the total area of land to be affected (in total) compared with the permitted area of 72 <br />acres. <br />7. The operator intends to stockpile topsoil above the highwalls west of the mining area. Please inform <br />the Division how the topsoiUoverburden piles will be protected from the mining operation. Due to <br />the location of the piles above the highwall, the topsoil piles may become unstable and slope failure <br />may occur if an adequate buffer distance is not established. Please demonstrate that the topsoil piles <br />will be stable under the proposed mining conditions using a slope stability analysis. <br />8. Other topsoil piles are noted being stored adjacent to the waste rock piles and the sediment control <br />berm. It appears that the topsoil piles located west of the sediment berm will ultimately be within the <br />"footwall benches". Rule 3.1.9(3) states that topsoil piles shall be stored in places and configurations <br />to minimize erosion and located in azeas where disturbance by ongoing mining operation will be <br />minimized. Please state how topsoil piles will be protected from the mining operation, benches and <br />any directed water flows in these particulaz locations. <br />9. The operator proposes to replace topsoil at a rate of 6" throughout the mine site and 12" on the mine <br />bettches. In several locations of the application, the operator states that from 1 foot to 5 feet (and up <br />to 6 feet) of topsoil is available for salvage in the newly permitted areas. In addition, Exhibit lb Soils <br />Map and the description of the soils included in the permit application states that a range of 20" to <br />60" of topsoil is available for salvage. The Division reviewed the topsoil balance in further detail and <br />determined the following: <br />Soil Ma Com lex Acrea a minus disturbed To soil D th Volume C <br />Moran Family Rock Outcrop <br />Teewinot Famil 38 20" 102,178 <br />Howazdsville-Leighcan Families <br />Com lex 11 60" 88,733 <br />Howardsville Famil 2 20" 5,378 <br /> <br />Total 51 196,289 <br />It appeazs that approximately 196,289 cy of topsoil can be salvaged from 51 acres of undisturbed <br />mine azea. Such volume of topsoil would cover 71 acres of disturbance at a uniform depth of 1.7 feet. <br />Based on the availability of topsoil in the permit azea, the operator will need to commit to a greater <br />topsoil replacement depth throughout the affected mined areas. The operator should consider a range <br />of depths that vary due to the benches, the waste pile cover and the mined area. <br />10. Please state if topsoil will be salvaged from the 1-acre staging area adjacent to Highway 50. Please <br />describe the location of any topsail piles to be stored in this area and specify the topsoil replacement <br />depth. <br />11. The operator states that benches will be 30' wide (at top) and 40' vertical height. Exhibit Cd depicts <br />benches 20' wide and 40' vertical height, and only the upper two benches are 30' wide. Please <br />explain this discrepancy. Also, please indicate installation of a safety bench at the very top of the <br />highwall. The highwall above this bench should not exceed 10 feet in height and wildlife escapway <br />ramps must be included. <br />12. The operator proposes a crushing and screening operation on site. Please locate these structures on <br />the mine plan map. <br />