2021-08-06_PERMIT FILE - C1982056A (2)

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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 2613, 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 26,13 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. In reference to the thickener underflow project, the reclamation work will involve removal of the pump, hosing and - piping, pump platform, support beams, powerline and poles, transformer, concrete pad, and grounding bed. The pump l will be removed from the pit, along with salvageable components, and then the remainder of the platform and support beams will be dozed into the pit. The powerline and poles and transformer will be salvaged and the concrete pad will be dozed into the pit. The grounding bed will be disconnected and left in-place and covered during the backfilling and grading of the surrounding area. The area then will be topsoiled and seeded in conjunction with the reclamation of the entire portal/facilities area. 18 Right Ventilation Shaft (TR04 44, TRO5 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 tilled 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 (Yrout 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 postnining 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. MR 15-294 2.05-105 02/02/16