2010-06-04_PERMIT FILE - C1982056A (9)

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• Installation of drainage and sediment control structures (includes 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 • Final clean-up and dressing of roads and site pad Site - specific investigations required for design and permitting of the new ventilation shaft 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. In order to reestablish effective vegetative cover, TCC will recover and stockpile a maximum of 18 inches of soil material from shaft disturbance areas. With a total road disturbance area of approximately 0.3 acres, approximately 750 CY of soil material will be salvaged from the road corridor, and approximately 12,800 CY from the 5.3 acre shaft pad and associated disturbance areas. Prior to initiation of soil salvage operations, temporary sediment control measures (silt fence, wattles, and/or other, as appropriate) will be installed. Soil salvage volumes are indicated on Table 49A. Soil material from the road corridor and other disturbance areas will be stockpiled in a central soil stockpile areas as shown on the design drawings in Exhibit 49R. Natural vegetative materials (mulch) incorporated into the soil, and seeding with the topsoil stockpile stabilization seed mixture identified on page 2.05- 121, will stabilize the stockpiled soil materials. Following soil removal, required drainage and sediment control structures will be constructed or installed. In order to minimize potential environmental and aesthetic impacts, surface drainage will be handled by a downslope drainage collection ditch; a culvert crossing where this ditch intersects the light -use road; Alternative Sediment Controls (ASC's) for the substation and soil stockpile; a partially incised two -cell sedimentation pond downgradient of the pad area; and a discharge control structure (rock check dam) and transition ditch at the outlet of the second sedimentation pond cell. TCC will apply for a modification to its existing CPDS Discharge Permit to include the new discharge point. The limited road drainage will be handled by a designed road ditch. In addition, the pad and light -use road will be gravel- surfaced to minimize erosion and sediment loss, other disturbed areas TR09 -66 2.05 — 45.6i 04/07/09