2014-11-20_REVISION - M1977036 (3)

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5. Exhibit E - Reclamation Plan 5.1 Final Grading, Revegetation, and Topsoiling 5.1.1 Final Grading Reclamation slopes within the Greeley 35 "' Avenue Mine West Pit will be constructed after the completion of the slurry wall and after completion of mining activities in the pit. The reclamation slopes will be constructed at a minimum 3:1 (H: V). 5.1.2 Slurry Wall Conventional slurry wall trenching techniques will be implemented for slurry wall construction along the Greeley 35th Avenue Mine West Pit slurry wall alignment. The slurry wall trench will be excavated to a width of 3.0 feet. Bentonite slurry will be used to stabilize the trench walls from collapsing. Select slurry wall backfill will be comprised of a mix of materials encountered during excavation of the trench mixed with bentonite trench slurry, powdered dry bentonite, and on -site or imported supplemental fines. The trench will extend from ground surface to a depth necessary to key the wall a minimum of five feet into unweathered bedrock underling the site. Exploratory boring results suggest the slurry wall trench depth (including key) should range approximately from 15 to 55 feet. The slurry wall alignment will encompass the West Pit in its entirety. A slurry wall construction platform varying in width from 40 to 95 feet in width (depending on slurry wall depth and proximity to existing structures) will be constructed to facilitate the construction of the slurry wall. The platform will be constructed on the pit side of the slurry wall alignment. Construction of the platform will require areas of cuts and fills along the alignment to bring the platform to the universal elevation of 4680.0. The typical side slopes in both the cut and fill areas will be 2:1 (H:V). These slopes are considered temporary, necessary only for construction of the slurry wall. Upon completion of the slurry wall, the fill slopes will be graded back to a 3:1 (H:V) in areas and utilized as reclamation slopes within the reservoir. The slurry wall alignment crosses the DCP 4 -inch gas transmission lines at four locations. The exact location and depth of these crossings is unknown, and will be developed during slurry wall construction. The buried pipelines will be encased in concrete extending 5 feet either side of the slurry wall. Several structural crossings will be constructed along the alignment allowing for vehicles and equipment to safely cross the slurry wall trench. Typical slurry wall sections are provided in Figure F -2. 5.1.3 Final Revegetation Revegetation will occur concurrently with or upon completion of the mining process. Care will be taken to regrade and provide reclaimed slopes such that revegetation regrowth may occur to