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a) Future industrial use of Mine Phases 2 through 4—When an industrial use is found for a mine <br /> phase/block(#), a technical revision will notify the Division Reclamation, Mining and Safety that <br /> the City of Evans has authorized a new industrial use for areas currently planned as General <br /> Agriculture reclamation. <br /> b) Adequate land area will be subdivided and developed as needed for the future heavy industrial <br /> use. Until a workable industrial use is found, reclamation of the property will be managed as <br /> general agriculture-dryland pasture. <br /> c) Mine phase 2, 3 and 4 will be filled with clean inert backfill from North to South.The mine <br /> blocks will be graded to contours consistent with the reclamation plan and similar to existing <br /> contours. Based on an estimated annual fill rate of 250,000 tons/yr., it will take ±45 years to <br /> complete the clean inert fill and final reclamation of mine phases 2 through 4. <br /> 4) The City of Evans 35th Avenue and PDC Energy's gas pipeline right of ways will be reclaimed as dry <br /> land pasture, except for permanent access roads. <br /> 5) BACKFILL-After an area of the property has been mined of sand and gravel, backfilling of the <br /> excavated areas will take place as the first step of the Stiles Mining Resource reclamation plan.The <br /> compacted backfill material will be placed in lifts from the bottom of the mine to within±6 inches of <br /> the land surface.ASO shall backfill the mined area with onsite overburden and inert materials that <br /> are compacted for stability. <br /> a) Backfill material will be imported to the mine with articulated dump trucks and/or highway <br /> dump trucks.The material will be placed, spread,and compacted in 1-to-2-foot lifts using a <br /> bulldozer, excavator, or loader. Compaction will take place during the filling process, as heavy <br /> trucks and equipment traverse over the fill. <br /> b) Backfill materials used within the affected area will be managed to prevent any unauthorized <br /> release of pollutants to the surface drainage system. <br /> 6) Completion of inert backfill with topsoil. <br /> a) After completion of the inert material backfill, a final topsoil cover±six(6) inches thick will be <br /> placed on top of the backfill to reach final grade.The topsoil layer will be seeded with a native <br /> grass seed mix to return the property to general agricultural—dryland pasture use.This material <br /> will be applied to all disturbed areas,with exception of industrial areas, permanent access roads <br /> and mine buffers. <br /> 7) The Site will be graded and returned to the approximate topographic elevations prior to mining.The <br /> approximate final contours of the Site are shown on Exhibit F- Reclamation Plan Map.The final <br /> grades will allow for the development of heavy industry uses.The final grades will allow general <br /> agriculture operations,farm machinery and livestock to traverse the area. <br /> a) There are no permanent steep slopes at the site. <br /> b) Temporary excavation slopes and temporary stockpiled material slopes may range from 1:1 to <br /> 3:1 depending on soil conditions in the mine. All slopes will be maintained for site safety and to <br /> minimize material erosion. <br /> c) Final grades will allow for site drainage to flow gently as sheet flow to northeast,consistent with <br /> pre-development drainage. <br /> d) The grading at Stiles Mining Resource shall control water runoff, erosion, and siltation to protect <br /> all areas outside the mine. During mining operations,the site will be graded, and best <br /> management practices will be used to keep all storm water on the site and within the mine <br /> boundary. <br /> H:\Pits HBP Plants\EVANS\Evans Mining Resource\DRMS Adequacy Revisions\Exh E Rec Plan REV 101822.docx <br />