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Section - 2.05.3 <br />II West Coal Refuse Facility -The 11 West Coal Refuse Facility site, located in the second <br />. significant ephemeral drainage to the west of the existing Elk Creek surface facilities, was selected <br />because the area provides sufficient disposal capacity for currently anticipated future mining <br />operations, it is readily accessible from the existing mine facilities, and upslope drainage can be readily <br />diverted. The II West Coal Refuse Facility will provide additional disposal capacity for approximately <br />380,000 cubic yards of coal refuse material. Based on projected mining rates, the additional available <br />capacity should be adequate to support current and anticipated future mining operations. The facility <br />will be accessed from the II West Haul Road. <br />The waste materials to be placed in the II West Valley Coa] Refuse Facility will be essentially the same <br />as those now going to the West Valley Coal Refuse Facility since they will come from the same or <br />similar sources. The stability of the II Wesr Valley Coa] Refuse Facility was analyzed using essentially <br />the same material characteristics as used in analyzing the East Yard and West Valley facilities and the <br />program SLOPE/W (GEO-SLOPE), which utilizes the limit equilibrium theory to determine a Factor <br />of Safett~. The stability analyses indicated a minimum static safety factor for the II West Valley coal <br />refuse pile slopes of ].53. The Il West Valley Coa] Refuse Facility was designed and it's stability <br />evaluated by Environmental Strategies Corporation (ESC), as documented by the design report <br />included in Exhibit 2.05-E4, Mine Development Rock/Coal Refuse Facility Design. <br />Soil materials from the II West Coal Refuse Facility will be recovered from the area bounded by the <br />railroad grade on the south and the north limit of the initial coal refuse bench. Soil recovery depth <br />(estimated at 4 to 5 feet) will be determined in the field based on visible soil chazactetistics and <br />operational considerations (rock content). The salvaged soils will either be hauled to the permitted <br />Upper Elk Creek soil stockpile or will be placed as a berm at the north soil stripping limit to be used <br />as cover material for the initial coal refuse bench. Medium to large rocks recovered during soil salvage <br />operations will be temporarily stockpiled adjacent to the foundation area for the initial coal refuse <br />• bench for use in constructing the underdrain. At any point in time, the area stripped for subsequent <br />waste placement and related activities is not anticipated to exceed approximately one-third of the <br />overall waste pile footprint. Surface drainage from the waste pile, stripped areas, and adjacent areas as <br />well as any infiltration intercepted by the underdrain will be routed to Sedimentation Pond E to allow <br />settlement of suspended solids prior to dischazge to the North Fork of the Gunnison River. <br />Coal refuse placement will involve hauling coal refuse materials to the base of the fill area, dumping <br />and spreading the material in horizontal lifts, and compacting the materials to design specifications. <br />The face of the fill slope is maintained at 2H:1V by stepping back each successive lift. At <br />approximately 50-foot increments, the nest lift is stepped back by approximately 10 feet and graded <br />into the slope to create slope breaks in the fill face to reduce overland flow and erosion and divert <br />surface runoff to the perimeter collection ditches. As fill height progressively increases, additional <br />areas above the active 5ll bench will be prepazed for refuse placement, with soil and rock recovery and <br />stockpiling and extension of the underdrain and perimeter collection ditches. The progress and timing <br />of waste pile construction will be wholly dependent on the amount of coal mine waste generated by <br />ongoing mining operations. This amount can vary significantly dependent on muting conditions but is <br />projected to range from approximately 3,000 to 6,000 cubic yards annually. <br />As each successive 50-foot fill bench is completed, it will be seeded, mulched, and a fabric matting <br />would be installed to protect the slope. Seeding mulching, and matting timing and techniques can be <br />varied to suit appropriate weather and site canditions. This process would be repeated until the <br />ultimate design fill height is reached. <br /> <br />TR-43 2.05-47b Revised August 2003 <br />