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III.A.8 Mine Ventilation A permanent fan has been installed at the D-Portal ventilation slope. <br />This fan operates in a blowing configuration pushing fresh air into the mine from the Ventilation <br />Entries and through the working area. It operates 24 hours per day, 365 days per year, with the <br />exception of scheduled maintenance periods. Detailed plans for the ventilation of the <br />underground working areas have been approved by MSHA. A ventilation shaft was constructed in <br />the B Seam which will be an exhausting return air shaft. Details of the shaft construction are <br />given on Map 151. The raised bored shaft is about 210 feet deep and 12-feet in inside diameter. <br />The shaft opening is covered with a heavy duty screen to control unauthorized access. The shaft <br />site is 100'x200'. Alight use road approximately 2410 feet long has been constructed from the <br />existing mine haul road to the shaft site (see Map 151). In anticipation of possible future power <br />requirements for the area, approximately 3400 feet of overhead electric utility lines may be <br />installed. See Map 151. <br />A return shaft (RS#1) was constructed and a return shaft (RS#2) will be constructed in the B- <br />Seam. This shaft will allow the return air to exhaust without a fan on the surface. RS#1 is about <br />300 feet deep. RS#2 is about 308 feet deep. RS#1 is five feet in diameter and lined with steel to a <br />finished diameter of four feet. RS#2 will be six feet in diameter and lined with steel to a finished <br />diameter of five feet. The upper and lower 20 feet of the annulus between the steel liner and the <br />shaft will be grout sealed in with concrete. The middle zone of the annulus will be gravel filled and <br />weep holes will be drilled in the line to allow drainage. Alight duty access road, approximately <br />8500 feet long, will be constructed. A 3-foot diameter, 362 foot deep ventilation shaft will be <br />drilled to the West Mains in the D-Seam. Map 153 shows typical details of the shafts, the <br />associated pad construction and proposed light use road. <br />During early 1987, gassy conditions were encountered at the Deserado Mine. To relieve those <br />conditions, BME drilled a 12-1/4 inch hole (LW1-1) and six (6) 10-5/8 inch holes (LW1-2 to LW1-7) <br />into the gob created behind the protective shield of the longwall 1. In September, 1988, a vent <br />hole (LW1-8) was drilled to relieve methane gas in the sealed area of the longwall panel #1 in <br />order to improve ventilation in other working areas of the mine. As of January, 1990, an additional <br />ten (10) 10-5/8 inch holes (LW2-1 to LW2-8, LW2-46 and LW2-6B) were drilled in the longwall #2 <br />and eleven holes (LW3-1 to LW3-11) were drilled in the longwall #3. Disturbance of the <br />archaeological site 5RB859 was mitigated. Hole LW3-12 in the longwall #3 and holes LW4-1 to <br />LW4-13 in longwall #4 were drilled in 1990. Holes LW4-14 to LW4-17 and LW5-1 to LW5-17 were <br />drilled in 1991. Holes LW5-8 to LW5-15 and LW6-1 to LW6-3 were drilled during 1992. <br />Ventholes LW6 to LW6-12 and LW7-3 to LW7-5 were drilled during 1993. Holes LW7~, LW7- <br />8, LW7-10, LW8-2, LW8-3 and LW8-5 were drilled in 1994. LW7-1 and LW7-2 were permitted but <br />not drilled because of the change in the start line location for LW-7. Also holes LW7-7, LW7-9, <br />LW8-1, LW8 and LW8-6 were permitted but not drilled. On January 31, 1996, the mine caught <br />on fire near LW-9 face. Emergency drill holes LW9-1 and LW9-2 were drilled to inject COZ. The <br />(Rev, 9/00) III-27 <br />