2016-08-12_REVISION - C1982056 (2)

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ventilation fan and associated equipment, emergency hoist equipment shaft heater, and electrical equipment will be removed and reused at another location, salvaged, or disposed of off-site. Concrete pads will be broken up and foundations will be demolished to at least 2 feet below grade, and the resulting concrete debris will be disposed of in the shaft opening. The upper 4 feet of the shaft collar and the concrete shaft slab will also be broken up and disposed of into the shaft opening. A cement plug will be placed in the bottom 15 feet of the shaft and the remainder of the shaft will be filled with inert material including the shaft cuttings and collar excavation materials. A cement plug will be poured from 10 feet below grade to within approximately 3 feet of the surface. The remaining 3 feet will be filled with soil, and graded to blend with the surrounding terrain. As noted in the discussion of construction for the 18 -Left Ventilation Shafts, any required pressure—grout boreholes will be sealed at the time of construction. Cement grout will be pumped through the boreholes to seal any wet zones encountered and the boreholes will be filled with grout and allowed to set-up on completion of grouting operations. Any surface casing extending above ground surface would be cut-off flush with or below natural ground level. The MAC borehole and Utility Borehole will be plugged and sealed using the same methods as previously described for the shaft seal. The pipeline will be reclaimed by cutting the ends of the pipeline off below the ground surface, capping the ends, and leaving the pipeline buried in-place. Following removal of structures and equipment, and plugging and sealing of the shaft and borehole(s); any cuttings remaining in the temporary mine waste disposal pit will be covered with excavated shaft collar material; road culverts will be removed and disposed of off-site; road -base and surfacing materials will be removed and placed on the shaft pad; and the shaft pad, substation area, sedimentation pond, and light -use road disturbance areas will be regraded to reestablish effective drainage and blend with the surrounding terrain. Cover over any cuttings remaining in the cuttings pit will be a minimum of 2 feet of suitable material, and the postmining configuration will approximate the premining contours. As -built certification will be provided to the CDMG following final closure, backfilling, and grading of the cuttings pit. Any excess road -base and surfacing materials not required to reestablish approximate original contour will be hauled off-site and disposed of. Stockpiled topsoil will then be replaced on those disturbed areas where it was previously removed and seeded with a pastureland seed mixture. 13 -Left Outby Utility Borehole (MR15-291) - The 13LT Outby Utility Borehole will have a limited life, being used only to support cementing operations in the final panel areas for the 12LT and 13LT Panels. When the borehole is no longer needed to support these activities, the borehole will be plugged and sealed, and surface disturbance areas will be reclaimed. A plug will be placed in the bottom of the borehole, cement grout will be pumped into the borehole to establish a bottom plug and to seal any wet zones encountered, the remaining borehole void will be filled with drill cuttings and/or suitable plugging materials to within five feet of the ground surface, a cement plug will be poured at the surface, and any surface casing extending above ground surface would be cut-off flush with or below natural ground level. Following plugging and sealing of the borehole, any mud pits will be allowed to dry -out and will be backfilled with the excavated material, road -base and surfacing materials will be removed and placed on the shaft pad; and the shaft pad and light -use road disturbance areas will be regraded to reestablish effective drainage and blend with the surrounding terrain. 9 -East Utility Borehole Installation - The 9 -East Utility Borehole Installation is expected to be actively used for only about three years to support operations in the 9- and 10 -East Wolf Creek longwall panels. When no longer needed, this installation will be reclaimed by plugging and sealing the boreholes, breaking -up and hauling the concrete pad materials off-site, regrading the pad and road areas, reestablishing drainage, replacing soil materials, and revegetating the disturbed areas. A plug will be placed in the bottom of the boreholes, cement grout will be pumped into the boreholes to establish a bottom plug and to seal any wet zones encountered, the remaining borehole voids will be filled with drill cuttings and/or suitable plugging materials to within five feet of the ground surface, a cement plug will be poured at the surface, and any surface casing extending above ground surface will be cut-off flush with or below natural ground level. Following plugging and sealing of the borehole, any mud pits will be allowed to dry -out and will be backfilled with the excavated material, road -base and surfacing materials will be removed and placed on the shaft pad; and the shaft pad and light -use road disturbance areas will be regraded to reestablish effective drainage and blend with the surrounding terrain. Stockpiled soil materials will be replaced, and the reclaimed areas will be reseeded with the permanent rangeland seed mix, consistent with the prevailing land use at the time of disturbance. MR16-302 2.05-106.1 08/12/16