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Satiar - 2.05.3 the Gseam to the surface. The rock slope extends about 200 feet in horizontal • distance, from elevation 6,042 to 6,097 at the surface. D. Mme Ventilation Installation -Two mine ventilation fans, associated fan housings and steel duff work, drive motors, and control equipment are installed near the return decline. A twelve-foot deep concrete shaft connects the return decline to the steel ductwork on the surface. A smaller fan was installed for the initial mine development in late 1991. A large fan was subsequently installed in 1993. The ventilation system is designed so either fan can be used to ventilate the mine to provide for a backup or supplemental ventilation capability. E. "C' Gulch Ventilation Shaft and Fan Installation - A ventilation shaft was constructed from the surface co a depth of approximately 450-feet co intercept the Sanborn Creek B Seam mine workings az a supplemental source of air to azsure adequate ventilation flows az mine workings are extended to the east and north. A concrete slab on the surface is connected to the shah collar, a grouted steel-plate liner extending to a depth of approximately 70 feet. The remainder of the shaft is supported by 6foot resin boles installed through wire mesh radially around the perimeter of the shah with 3-inches of shotcrete over the wire mesh to provide a smooth shah lining and reduce resistance to airflow. A ventilation fan has been installed on the GGulch Ventilation shah to increase ventilation airflow and pressures. The fan installation coasisu of a ventilation fan, steel fan housing and ductwork, drive motor, and fan controk mounted on a concrete slab foundation. Power is provided to the fan drive motor by a drop-line from a nearby transmission pole with direct power feed from the nearby Substation No. 3. Because the fan installation is close to old I-3ighway 133, it is surrounded by a • chain-link securiryfence with locked gate to limit public access. Temporary facilities including a hoist frame, hoist winches, shop, and water storage tank and pump, installed for shaft construttion have been removed and associated disturbance areas reclaimed once shah constmction was completed. A short segment of light-use road approximately 100-feet in length provides access for inspection and maintenance. Soil material from the shaft disturbance area was recovered and stockpiled in the existing Substation No. 3 soil stockpile for future use in reclaiming the site. Soils are relatively deep in this area and soils were salvaged to a depth of approximately 4-feet, resulting in recovery of approximately 3,000 cubic yards of soil material. The shaft excavation material was placed underground in previously mined-out areas. F. Electrical Substation No. 2 - A fenced substation, located in the Sanborn Creek Mme portal area, is designed to provide electrical power to the mine, ventilation fan, and overland conveyor. Prirrtary power is supplied from aDelta-Montrose Electric overhead powerline. G. Electrical Substation No. 3 - A fenced substation u located approximately two miles east of the Sanborn Creek Mme portak along old State Highway 133. The substation u designed to provide electrical power to the mine through a borehole. Primary power is supplied from aDelta-Montrose Electric overhead power line. H Degazsification Boreholes -Boreholes have been or will be drilled from the surface to intercept the underground mine workings in order to bleed-off accumulations of ~rtetur~rt "Kaz e~ -prevrn, •;r,rcerrir]Jry ~r~tgentu~ gaz ~relr~e 4rurt, •hte a-e•1reL tmderground mine workings. Approximate borehole locations are shown on the Mute Area Geology Map, (Map 2.04-M3). The exact location and orientation of each borehole is detemtirted through surface and underground surveys to assure interception and effective degassification of the mine workings. To date, five degassification Boreholes (B-4, 5, 6, 7, and 8) have been completed into the Somerset PR04 2.05-19 Revised May 2001