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10/21/2004 13:07 19709295177 <br />Seaiava• 2,05.3 <br />OXBOW MINE <br />PAGE 04109 <br />G Declines to the GSeam -Three declines, including the intake, beltline, and rerun <br />entries and the associated concrete, structural steel and corrugated metal face-up <br />structures extend from the finished grade at the Sanborn Cheek Mrne portal area <br />down to the GSeam. The declines extend about 70 feet' in horvontal distance, #rom <br />elevation 6,057 1A 6,044. During 1995, an additional rock slope was developed from <br />the Gseam to the surface. The rock slope extends about 200 feet in horizontal <br />distance, from elevation b,042 to 6,097 at the surface. <br />D. Mute Ventilation Installation -Two mine ventilation fans, associated fan housings <br />and steel duct work, drive motors, and control equipment are installed near the <br />return decline. A twelve-foot deep concrete shaft connects the return decline to the <br />steel ductwork on the surface. A smaller fan was installed for the initial mine <br />development in late 1991. A Loge fan was subsequently installed in 1993. The <br />ventilation system is designed so erther fan can be used to ventilate the mine to <br />provide for a backup or supplemental ventilation capability. <br />E. "C' Gulch Venolation Shaft and Fan Installation A ventilation shafr was <br />constructed from the surface to a depth of approximately 450-feet to intercept the <br />Sanborn Cheek B Seam mice workings as a supplemental source of air to assure <br />adequate ventilation flows as mine workings are extended to the east and north, A <br />concrete slab oa the surface is connected to the shaft collar, a grouted steel-plate <br />liner extending to a depth of apprordmately 70 feet, The remaintder of the shaft is <br />supported by 6-foot ream bolts installed through wire mesh radially azound the <br />peruneter of the shaft with 3-inches of shotcrete over the wire mesh to provide a <br />smooth shaft lining and reduce resistance to airflow. <br />A ventilation fan has been installed oa the GGulch Ventilation shaft to increase <br />ventilation airflow and pressures. The fan installation consists of a ventilation fan, <br />steel fan housing and ductwork, drive motor, and fan controls mounted on a <br />cohcrete slab foundation. Power is rovided to the fan drive motor by a drop-line <br />fmm a nearby transmission pole with direct power feed from the nearby Substation <br />Nb. 3• Because ehe fan installation is close to old Highway 133, is is surrounded bya <br />chain-link security fence with locked gate to limit public access. <br />Temporary facilities including a hoist flame, hoist winches, shop, and water storage <br />tank and pump, installed for shaft construction have been removed and associated <br />disturbance areas reclaimed once shaft construction was completed. A short <br />segment of light-use road approximately 100•feet in length provides access for . <br />inspection and maintenance. <br />So>7 material from the shaft disturbance area was recovered and stockpiled in the <br />existing Substation No. 3 soil stockpile for future use in reclaiming the site. Soils are <br />relatively deep in this area and soils were salvaged to a depth of approximately 4-feet, <br />resulting in recovery of apprrordarately 3,000 cubic yards of soil material, The shaft <br />excavanon material was placed underground in previouslymined•out areas. <br />F, Electrical Substation No. 2 - A fenced substation, located is the Sanborn Creek Mme <br />portal area, is designed to provide electrical power to the mine, ventilation fan, and <br />overland convveeyyoor. Primary power is supplied from a Delta-Montrose Electric <br />ovedread powerline. <br />G. Electrical Substation No. 3 - A fenced substation is located approxima[ely two miles <br />east of the Sanborn Creek Mine portals along ok{ State I-hghwayy 133. The <br />substation is designed to provide electrical power to the mine through a borehole;. <br />Prirnarypower is supplied from aDelta-Montrose Electric overhead power line. <br />Degasification Boreholes -Gob vent boreholes have been or will be drt7led from the surface <br />to intercept the underground mine workings in order to bleed-off accumulations of methane <br />gas and prevent pot¢atially dangerous gas seepage from the sealed underground mine <br />TR4fl 2.05-19 Rn,rie...7 (lrrnt... '1M~ <br />