2011-06-20_PERMIT FILE - C1982056A (8)

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18 -Left Ventilation Shaft (MR09 -235, MR10 -249, MR10 -250, TR 09 -66, TR09 -70) As mine development proceeds to the west in the Western Mining District (WMD), the distance from existing mine ventilation shaft and fan installations will increase to the point where additional intake and exhaust ventilation shafts are necessary to maintain effective ventilation of active mining areas. In order to minimize surface disturbance and simplify operation, the new intake and exhaust shafts will be established at the same location. The proposed new ventilation shafts will be located in close proximity to Routt County Road 27 in the NW' /SW'/ Section 23, T5N, R87W on a shallow slope near the crest of a small ridge in an area of open pastureland, as shown on Map 23. Development, construction, and installation of the ventilation shafts and associated fan and ancillary facilities will involve the following sequential activities, as briefly described in the following sections and shown on the design drawings provided in Exhibit 49R: • 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 control structures (includes two -cell sedimentation pond) • Construction of a light -use road and site preparation for shaft pad • Construction of the shaft pad and lined cuttings pit • Drilling and casing of an exploration borehole to verify geologic and groundwater conditions • Substation construction and installation of electrical distribution line and equipment • Grouting operations (as necessary) and drilling of shaft pilot holes • Excavation and construction of shaft collar structures • Blind - drilling and casing of two shafts • Installation of mine ventilation fan, fan shroud, silencer, equipment building, and associated equipment and controls on ventilation exhaust shaft • Installation of shaft heater and associated ancillary equipment on ventilation intake shaft • Erection of escape hoist building and installation of equipment and controls on ventilation intake shaft • Construction of security fence around shafts • Extension of entries from the 18 -Left longwall panel to connect to the shaft bottom • Conversion of the exploration borehole to a Mine Atmosphere Control borehole, and installation of modular methane drainage and/or nitrogen injection systems • Boring and casing of a mine dewatering borehole and installation of a pumping system and controls • Boring and casing of utility borehole and installation of rock -dust drop pipe, rock -dust tank and controls, and compressed -air pipe • Installation of compressor building, compressors, and associated control equipment • Installation of a mine water transfer pipeline, associated valving, and access manholes • Final clean -up and dressing of roads and site pad Site - specific investigations required for design and permitting of the new ventilation shaft and pipeline will, or have included a cultural resource survey of potential disturbance areas, soil and foundation characterization as the basis for shaft pad and access road design, vegetation community mapping, and verification of TES compliance. The cultural resource survey was conducted by Metcalf Archaeological Consultants, the engineering soils characterization by Northwest Colorado Consultants, and the soils /vegetation investigations by Habitat Management. The perimeter of all areas affected by surface facilities construction will be clearly marked before the beginning of surface disturbances. The proposed shaft pad and cuttings pit will have maximum dimensions of approximately 425 x 500 feet (4.5 acres) with cut and fill slopes, and the substation area will be approximately 80 x 125 feet. The substation and powerline disturbance, light -use road, and soil stockpile area will add approximately 1.1 acres of disturbance, for a total disturbed area of approximately 5.6 acres. The light -use road disturbance corridor will be approximately 420 feet long and 40 feet wide (0.3 acres of disturbance). Actual constructed road width (finished top width) is expected to be approximately 24 feet. Refer to Exhibit 25Y, 18LT Ventilation Shaft Installation — Foundation and Road Investigations, Map 24 (Sheet 4 of 4), and Exhibit 49R, 18LT Ventilation Shaft Installation — Design Drawings, for details on the road, and the road profile and cross - section. The proposed light - use road crosses upland areas where road construction will involve removal of any large vegetation and stripping and stockpiling of other vegetation, soil, and organic materials. MR10 -250 2.05-45.15 12/02/10