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previously disturbed site and within TCC's existing sediment control system. The overburden storage area is <br />located on a gentle slope to the south of the pit I. The cuttings will be transported and incorporated into the coal <br />waste disposal when weather allows in summer 2002. Prior to incorporating the cuttings into the site, a geotechnical <br />analysis will be submitted demonstrating cuttings will not jeopardize the integrity of the site. Once [he cutter head <br />breaks through to the surface within the shaft collar, the cutter head, drive unit, and temporary headframe will be <br />disassembled and removed from [he site. A permanent shaft casing <br />consisting of steel ring beams and liner plate will be placed and the annulus between the liner and the shaft bore <br />will be cemented in segments after boring operations progressed to the surface. <br />The cement shaft liner will serve to isolate the Twentymile Sandstone from the Wadge Overburden. Additionally, it <br />is planned to pressure grout the Twentymile Sandstone to prevent seepage from it into the shaft. This will further <br />ensure that after final closure the water in this unit will be confined and not seep down on the inside of the shaft. <br />Following completion of shaft boring and casing operations and removal of equipment from [he site, the fan <br />enclosure (fan shroud) and electrical control building will be erected on either [he previously constructed or new <br />concrete pads and the fan, fan drive motor, and electrical control, monitoring, and communication systems will be <br />installed. Average pad thickness will be 2' and total pad surface area will be approximately 3100sf. The installed <br />axial-vane exhausting ventilation fan has a capacity of 800,000 cfm with a 3000 hp drive motor. A fence will be <br />constructed to enclose the fan installation. Following commissioning, [he shaft pad site and access road will be <br />cleaned-up and surface areas graded and dressed <br />Concurrent with road construction a power distribution line will be extended from the existing substation to the <br />pad-mounted transformer at the shafr site. The power distribution line is approximately 3,600' long with a total of <br />12 power poles. <br />In order to minimize potential environmental and aesthetic impacts associated with the NW Mains ventilation shaft <br />and fan installation, surface drainage at the shaft site will be handled by an upgradient diversion ditch, perimeter <br />berms, and gravel surfacing under an SAE, the limited road drainage will be handled by designed drainage <br />structures, active use areas are graveled to control dust and drainage, other disturbed areas (including topsoil <br />stockpiles) will be stabilized with temporary vegetation, and structures will be painted in neutral earth-tone colors <br />[o blend with the natural surroundings. <br />As shown on Map 23, additional entries will be driven to the north from the ventilation shaft site. These entries will <br />be needed to maximize the efficiency of the ventilation system. The entries will be driven in the same manner as is <br />used in TCC's development work, i.e. continuous miners and shuttle cars. <br />No. 7 North Escape Shaft (Section 20, TSN, R86W) <br />A 1,066 foot escape borehole shaft was constructed into #7 entry of North Mains to allow emergency evacuation of <br />personnel from the development sections of the 9 Right and ]0 Right gateroads. The construction of the shaft <br />utilized raise drilling techniques. It is anticipated that the escape shaft will be utilized for approximately ten years. <br />The site is shown on Figure 23, General Location of Escape Shaft. <br />The drilling of the shaft resulted in minimal surface disturbance. A drill pad approximately 200' x 200' was <br />constructed at the resulting site in 1,450 CY of cut and fill. Available topsoil was salvaged and stockpiled for <br />future reclamation of the site immediately northeast of the drilled pad. Approximately 18" of topsoil derived from <br />Cochetopa Loam is available for salvaging (222 CY). Casing and other drilling supplies were stockpiled on the <br />borehole pad. <br />After topsoil removal, two mud pits with dimensions of 10' x 10' x 7.5' were dug adjacent to the drill hole. <br />Drilling fluids and cuttings were discharged into the adjacent pits, allowing settling in one pit with water decanting <br />MR 02-176 2.05-45.2 02/20/02 <br />