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6.4.4 Exhibit D -Mining Plan <br />6.4.4.1 MINING METHODS <br />All of the mining operation will be "dry" mined. Trenches will be dug around the <br />perimeter of each mining cell for dewatering purposes. Operations will <br />incorporate conventional aggregate mining methods, including the use of <br />scrapers and dozers to strip overburden, scrapers and backhoes to move and <br />load sand and gravel, and haul trucks to move mined-material. The operation will <br />mine and reclaim the land concurrently. <br />6.4.4.2 EARTHMOVING <br />The north end of the proposed site is currently being mined under the existing <br />111 Permit M-2003-090. There is currently an area of approximately 10.5 acres <br />that has been disturbed by this mining operation and is open to a depth varying <br />between 5 and 8 feet below the existing ground surface surrounding the <br />excavation. The existing pit, once mined, will be used to accept stockpiled <br />overburden from mine areas in the northern portion of the site, where additional <br />mining under this permit will then follow. Following overburden removal, gravel <br />extraction will occur. <br />Generally, the proposed mining will begin in the previously mined area (Cell A} <br />and proceed sequentially to Cell K as shown in Exhibit C-Mining Plan. Mining will <br />move counterclockwise around the edges. of the West Pit. Approximately 15-20 <br />acres of surface area will be mined per year. As overburden or waste material is <br />removed, it will be placed in an existing stockpile area or in an area that was <br />previously mined. Adequate overburden volume will be left to backfill adjacent oil <br />and gas structures. One oil and gas structure area to be backfilled will be open <br />at any one time. The approximate average backfill volume need to backfill <br />adjacent to an oil and gas structure area is 85,000 yd3. As gravel extraction <br />progresses, concurrent reclamation operations will also proceed. Backfilling of <br />waste material adjacent to oil and gas structures will occur no later that two <br />weeks following excavation - as indicated in Exhibit C-Mining Plan. <br />Temporary and permanent offsets around oil and gas structures as well as the <br />roads that serve these structures have been shown in Exhibit C. No mining will <br />occur within these offset areas in order to protect the existing structures. <br />Temporary offsets of 75-feet are provided for each well during mining activities. <br />Once mining is completed in the area of a well, enough overburden will be placed <br />around the well to achieve 150-feet of offset from the well with a 3:1 slope to <br />natural ground and 2:1 slope to the bottom of the pit. Likewise, roadways that <br />access oil and gas wells within the gravel mining operation will be provided with <br />10-feet of temporary offset during mining activities. When mining activities are <br />completed in the area, enough overburden will be placed to provide 20-feet of <br />offset from the centerline of the road. Mining will not occur closer than 200 feet <br />from any oil and gas structures prior to the execution of agreements allowing <br />mining to occur closer. <br />File Pit 112 DMG Permit Application Rev 1.0 <br />Page 2 or 27 <br />