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sealed, and surface disturbance areas will be reclaimed. The supporting equipment and any structural steel or tanks will <br />be removed and reused at another locale, salvaged, or disposed of off -site. Buried utilities will be stubbed -off below <br />•grade and abandoned. Concrete pads will be broken up, and foundations will be demolished to at least 2 feet below <br />grade, and the resulting concrete debris will be disposed of in the shaft opening. The shaft collar concrete will also be <br />broken up and disposed of into the shaft opening, leaving an open space for the concrete slab and backfill material/shaft <br />cuttings to be placed in the shaft void. A cement plug will be placed in the bottom 15 feet of the shaft and the <br />remainder of the shaft will be filled with inert material including the shaft cuttings and collar excavation materials. A <br />cement plug will be poured from ten feet below grade to within approximately 3 feet of the surface. The remaining 3 <br />feet will be filled with soil and graded to blend with the surrounding terrain. <br />As noted in the discussion of construction for the 6 -Main North Ventilation Shaft, any required pressure —grout <br />boreholes will be sealed at the time of construction. Cement grout will be pumped through the boreholes to seal <br />any wet zones encountered and the boreholes will be filled with grout and allowed to set -up on completion of <br />grouting operations. Any surface casing extending above ground surface would be cut -off flush with or below <br />natural ground level. At such time as the 6MN Temporary Shaft Heaters are no longer needed to address the <br />immediate shaft icing problems, the portable shaft heaters will be disconnected from the propane tank and electrical <br />connections, the vent tubing will be disconnected, and all systems components (ie: portable heater units, vent <br />tubing, and propane tank), will be removed from the site. Utility boreholes will be plugged, filled to within 10 feet <br />of the ground surface with inert material, and a cement plug will be poured from the top of the fill to within <br />approximately 3 feet of the surface. Any surface casing will be cut -off below grade, and the remaining hole will be <br />filled with soil material and graded to blend with the surrounding terrain. <br />The site geotechnical auger -holes and test pits were backfilled and leveled, and piezometers were either removed, or <br />plugged, cut -off below the ground surface, and capped with a clay or cement cap immediately following completion of <br />field investigations. The associated disturbed areas were seeded with the pastureland seed mixture within 6- months of <br />completion of the geotechnical investigations. Following removal of structures and equipment, and plugging and <br />•sealing of the shaft and boreholes, any cuttings remaining in the temporary mine waste disposal pit will be covered with <br />excavated shaft collar material; road culverts will be removed and disposed of off -site; road -base and surfacing <br />materials will be removed and placed on the shaft pad; and the shaft pad and access road disturbance areas will be <br />regraded to reestablish effective drainage and blend with the surrounding terrain. Cover over any cuttings remaining in <br />the cuttings pit will be a minimum of 2 feet of suitable material, and the postmining configuration will approximate the <br />pre - mining contours. As -built certification will be provided to the CDMG following final closure, backfilling, and <br />grading of the cuttings pit. Any excess road -base and surfacing materials not required to reestablish approximate <br />original contour will be hauled off -site and disposed of. Stockpiled and windrowed topsoil will then be replaced on <br />those disturbed areas where it was previously removed and seeded with a pastureland seed mixture. <br />The surface disturbance resulting from construction of the mine water pipeline running from the 6MN Million - Gallon <br />Tank to the 10 -Right Dewatering Pipeline, was reclaimed concurrently with pipeline installation. After placement of <br />the pipeline in the excavated trench, the excavated material was backfilled into the trench and compacted around and <br />over the pipeline, topsoil which had been windrowed to the side of the trench excavation was re- spread over the <br />disturbed area, and disturbed areas were reseeded with the standard rangeland seed mixture. When use of the pipeline <br />is no longer necessary to support ongoing or future mining operations, the pipeline will be plugged and stubbed -off <br />below grade at both ends, and abandoned in- place. <br />18 -Left Ventilation Shaft Installation (MR10 -249 MR10 -250, TR09 -66 TR09 -70) <br />When the 18 -Left Ventilation Shaft, emergency hoist equipment, shaft heater, and MAC borehole(s), Utility Borehole, <br />and rock -dust tank are no longer required to support ongoing or future mining operations, the associated surface <br />facilities will be removed, the shaft and borehole will be plugged and sealed, and surface disturbance areas will be <br />reclaimed. The nitrogen injection system equipment is all skid mounted, and will be removed for use at another <br />• location. The mine ventilation fan and associated equipment, emergency hoist equipment shaft heater, and electrical <br />equipment will be removed and reused at another location, salvaged, or disposed of off -site. Concrete pads will be <br />broken up and foundations and support piers will be demolished to at least 2 feet below final grade, and the resulting <br />concrete debris will be disposed of in the shaft opening. The upper 4 feet of the shaft collar and the concrete shaft slab <br />MR10 -250 2.05-106 <br />12/02/10 <br />