2014-11-17_PERMIT FILE - C1982056A (3)

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concrete will also be broken up and disposed of in the shaft opening, leaving an open space for the concrete decking, concrete slab and backfill material to be placed in the shaft void. Shaft plugging and sealing will involve construction •and placement of a pre- fabricated framework of steel support beams, steel composite decking and 4 inches of concrete to be placed at the bottom of the shaft collar (approximately 20 feet below grade), which will rest on the lower shaft liner. Once this is completed, a 24 -inch thick reinforced concrete slab will be constructed over the previously placed slab and decking. The concrete in this slab will also flow down and fill -in the annular space between the C- channel and surrounding strata as shown in Exhibit 26B, Section 3 /S -1. This will effectively seal the plug at the interface of the plug and lower shaft liner. Also, tie -ins will be placed around the periphery of the 24 -inch slab to allow for tying -in the rebar of the reinforced concrete slab. After this slab has cured, backfill material will be placed in the void. The backfill material will be placed to within 6 inches of the surface, and the final 6 inches will be filled with topsoil. The plug drawing is presented in Exhibit 2613, NW -Mains Ventilation Shaft Plug. Following removal of structures and equipment and plugging and sealing of the shaft; road surfacing materials and culverts will be removed and disposed of off -site; and the shaft pad and access road disturbance areas will be graded to reestablish effective. drainage and blend with the surrounding terrain. Stockpiled and windrowed topsoil will be replaced on those disturbed areas where it was previously removed, and the areas will be seeded with a pastureland seed mixture. 18 -Right Ventflation Shaft (TR04 -44, TR05 -50, MR04 -190, MR05 -200, MR07 -225, MR08 -229, MR09 -234) When the 18 -Right Ventilation Shaft, emergency hoist equipment, and shaft heater and MAC borehole(s) are no longer required to support ongoing or future mining operations, the associated surface facilities will be removed, the shaft will be plugged and sealed, and surface disturbance areas will be reclaimed. The emergency hoist equipment and shaft heater 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 shaft collar concrete will also be broken up and disposed of into the shaft opening, leaving •an open space for the concrete slab and backfill material/shaft cuttings to be placed in the shaft void. A cement plug shall 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 on page 2.05 -45.4, 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(s) will be plugged and sealed using the same methods as previously described for the shaft seal. 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 and access 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 and windrowed topsoil will then be replaced on those disturbed areas where it was previously removed and seeded with a pastureland seed mixture. 6 -Main North Ventilation Shaft and Mine Water Storage Reservoir (TR05 -48, TR07 -61, TR07 -62, MR06 -208 • MR06 -210, MR06 -212, MR07 -224) When the 6 -Main North Ventilation Shaft and supporting equipment and boreholes are no longer required to support ongoing or future mining operations, the associated surface facilities will be removed, the shaft will be plugged and RN08 -05 2.05-105 03/12/10