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EXHIBIT D— Mining Plan (Revised 08/18/2020) <br /> a) Description of Methods: The area will be stripped so that the crushing and screen plants can be set <br /> up on the west end of the permitted area. Topsoil thicknesses at the Koskie site are thin, typically <br /> less than 12 (twelve) inches. Topsoil will be stockpiled mainly on the western perimeter of the <br /> mining area and will be seeded to prevent erosion and loss of soil. Some stockpiling may occur on <br /> the eastern perimeter of the mining area and previous stockpiling has occurred on the northern <br /> perimeter as well. Please see Exhibit C3 for depiction of the topsoil stockpile areas. Mining will <br /> start on the east end of the permitted area and progress to the west,generally moving north to south. <br /> It is anticipated that mining will be done using excavators, front end loaders, dozers, scrapers, and <br /> haul trucks. Best Management Practices, including berms, silt fencing, and straw bales erosion <br /> control measures will be installed along the east end of the Koskie site to protect the adjacent <br /> intermittent creek area from mined area runoff and sediment. Open excavations are not anticipated <br /> to be over 15 feet deep, MS1 A approved open excavation and fall protection safety measures <br /> including fencing and berms will be installed as needed. During and following mining, side slopes <br /> to the pit will be graded for stability and will be re-vegetated as needed to meet the reclamation <br /> plan. <br /> b) Earthmoving: Excavation and stockpiling volumes are anticipated to be approximately 100,000 to <br /> 150,000 tons per year. It is anticipated that topsoil and overburden will be removed and stockpiled <br /> using scrapers. The scrapers will create drive-over stockpiles that will then be seeded and stabilized <br /> using the reclamation seed mix. <br /> It is anticipated that mining will be done using excavators,front end loaders,dozers, scrapers,and <br /> haul trucks. Most of the mining is expected to be done by dozers pushing pit run material into <br /> stockpiles located near the crushing plant. Front end loaders will be used to take the pit run <br /> material from the stockpile and feed it into the plant. As mining operations move further from the <br /> plant, excavators will be used to load pit run material haul trucks. The loaded haul trucks will <br /> then take the pit run material to stockpiles located near the crushing plant. Front end loaders will <br /> take the pit run material from the stockpiles and feed it into the plant. <br /> Best Management Practices, including berms, silt fencing, and straw bales erosion control <br /> measures will be installed along the east end of the Koskie site to protect the adjacent intermittent <br /> creek area from mined area runoff and sediment. <br /> Open excavations are not anticipated to be over 15 feet deep, MSHA approved open excavation <br /> and fall protection safety measures including fencing and berms will be installed as needed. <br /> During and following mining, side slopes to the pit will be graded for stability and will be re- <br /> vegetated as needed to meet the reclamation plan. Highwall mining is not anticipated. It is <br /> anticipated the pit will be mined to conform to the 4:1 reclamation slope. In the rare event that a <br /> highwall is created, the highwall is not expected to exceed 15 feet and a minimum of 20 feet <br /> separation between the highwall and mining boundary will be maintained. Highwall conditions <br /> will be eliminated by reducing the slope to a 4:1 slope as quickly as possible. In the event highwall <br /> conditions are created,MSHA rules and regulations will be followed to prevent injury and damage <br /> to equipment. <br /> c) Water Diversions and Impoundments: The Koskie property is located approximately '/2 mile west <br /> of Lone Tree Creek which is an intermittent stream that is typically dry most months of the year. <br /> There are no irrigation structures, surface water impoundments, or water diversions existing or <br /> anticipated at the site. Test pitting performed at the Koskie site shows that groundwater is deeper <br /> M:\Mining\Koskie\DRMS\DRMS Application\Amendment to Expand Acreage\Adequacy Review Response 08-18-20.docx <br /> Page 3 of 5 <br />