2014-04-25_PERMIT FILE - C1982056A (3)

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inches of suitable roadbase materials and 8 inches of pit -run gravel. It is anticipated that two to three turn-outs (up to 30 -foot wide) will be constructed in flat straight areas along the road to allow passing of heavy trucks. The 24- foot road surface will be graded and crowned, or sloped into the hillside, to promote effective drainage. Construction of the borehole pad will involve soil recovery, installation of drainage structures, cut /fill pad construction, and placement of gravel surfacing material to control dust and sediment from the pad area. Borehole completion will involve drilling, installing, and grouting a 20 -inch diameter steel surface casing in place to a depth of up to 80 feet (dependent on the ground conditions encountered). The borehole will then be advanced, using directional drilling, to a depth of approximately 1,700 feet to intercept the mine workings. Water, drilling fluids, and cuttings will be contained within one or more portable steel tanks (porta -pits) on the borehole pad. The borehole will be drilled to a nominal diameter of 17 inches, and three welded steel carrier pipes, one 6.625, and two 2.375 inches in diameter, will be suspended in the borehole and grouted in. A collar for pumping concrete or portable fabricated steel chute will be fitted to the larger carrier pipe for concrete and material drops. Concrete or other materials will be transferred underground using a pipeline or underground equipment to the location(s) where they will be used. The 16LT Utility Borehole installation will remain in -place until it is no longer needed to support ongoing or anticipated future mining operations. Reclamation of this installation will involve plugging and sealing the borehole, regrading the pad and road areas to their approximate original configuration, soil material replacement, and reseeding with TC's standard Pastureland Seed Mixture, or an alternate seed mix, if requested by the surface landowner. 15 -Left Ventilation Shaft (TR11 -77) As a result of progressive mine development in the Western Mining District (WMD) and expanded MSHA rock - dusting requirements, a new ventilation bleeder shaft and additional rock -dust transfer location will be needed to support ongoing mining operations. The proposed new ventilation shaft will be located off the existing light -use road serving the Fish Creek Water Treatment Facility in the SW' /SE'/ Section 24, TSN, R87W, as shown on Map 24. Development, construction, and installation of the ventilation shaft and associated ancillary facilities will involve the following sequential activities, as briefly described in the following sections and shown on the design drawings provided in Exhibit 49Y: • Completion of environmental and engineering investigations • Placement of disturbed area markers • Temporary drainage and sediment control measures • Recovery and stockpiling of available soil materials • Installation of drainage and sediment controls • Construction of a light -use road and site preparation for shaft pad • Construction of the shaft pad and lined cuttings pit • Installation of electrical distribution line and equipment • Excavation and construction of shaft collar structure • Blind- drilling and casing of the shaft • Construction of security fence around the shaft • Extension of entries from the 15 -Left gate -roads to connect to the shaft bottom • Installation of rock -dust drop pipe, rock -dust tank, and controls • Final clean -up and dressing of road and site pad Site - specific investigations required for design and permitting of the new ventilation shaft and pipeline include a cultural resource survey of potential disturbance areas, identification and marking of wetland limits, and wildlife consultation. The cultural resource survey was conducted by Metcalf Archaeological Consultants, with results summarized by the survey report included in Exhibit 6T. The wildlife consultation is documented by a consultation letter from the CDOW, provided in Exhibit 23C. The perimeter of all areas affected by surface facilities construction will be clearly marked before initiating any surface disturbance. The proposed shaft pad, cuttings pit, and soil stockpile area will have maximum dimensions of approximately 200 x 350 feet (1.6 acres) with cut and fill slopes. The light -use road, will add approximately 0.7 acres of disturbance, for a total disturbed area of MR12 -260 2.05-45.23 04/12/12