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2.05 APPLICATION FOR PERMIT FOR SURFACE OR UNDERGROUND MINING ACTIVITIES - MINIMUM <br />REQUIREMENTS FOR OPERATION AND RECLAMATION PLANS. <br />S Room and pillar panels were developed off the main and submain entries with barrier <br />pillars left for protection. Pillars and barrier pillars were recovered to the extent safety <br />to the miners and machinery allowed. Where conditions precluded total extraction, <br />pillars were only partially removed, which temporarily delayed the planned roof falls <br />associated with pillar recovery. <br />Ventilation <br />The mine is currently sealed and the ventilation shafts and fans are removed and <br />backfilled. When operational, the mine used an exhausting ventilation system. Mining <br />was performed in small districts which were sealed after extraction in order to maximize <br />ventilation efficiency. Ventilation is closely monitored by mine officials and inspection <br />agencies and conforms to mine specific approved ventilation plans. Because Bowie <br />No. 1 is now closed and sealed, it no longer has an approved ventilation plan. <br />Roof Control <br />At the Bowie No. 1 Mine, the coal Seam is overlain with mudstone as the immediate <br />roof. The mudstone is unacceptable as the immediate roof. It is thinly laminated clay <br />and silt which is commonly rooted and vertically fractured by the dense cleat system <br />and slickensides. When used as immediate roof, this material spalls out in large <br />chunks before roof bolts can be installed. Once exposed to air, the mudstone <br />deteriorates as air and water in the mine atmosphere cause it to separate and fall. The <br />poor roof conditions created by this mudstone roof is made worse by the presence of <br />meandering sand channels found throughout the mine roof. <br />. Historically, acceptable roof conditions are established when three feet of top coal is <br />left in place as a beam to support the mudstone immediate roof. Eight foot long roof <br />bolts are used to support the roof, along with timbers, ground cribs and other roof <br />support devices as needed. <br />Production Rate <br />Mining ceased at the Bowie No. 1 Mine on December 4, 1997. There are no plans to <br />reinitiate coal production at the Bowie No. 1 Mine. <br />Historically, the mine produced coal at a rate of between 0.5 and 1.5 million tons per <br />year. This run -of -mine production was transferred to a crushing and screening plant <br />via a downhill conveyor system with a 2,000 ton surge capacity. Large rock, metal and <br />other extraneous materials were removed before the product was screened to minus 2 <br />inches. The prepared product was then trucked to the Bowie No. 1 Unit Train Loadout, <br />located near the Union Pacific Railroad just south of Highway 133 and just east of <br />Paonia. <br />Major Equipment <br />The mine is closed and all machinery removed. Historically, the mine used ripper style <br />continuous miners for coal extraction. <br />The cavity made by the extraction of coal was then supported by drilling holes in the <br />mine roof with roof bolting machines and then inserting fully resin grouted headed rebar <br />into the mine roof. Bolts were typically eight feet in length and were generally used in <br />• conjunction with roof mats. The roof mats controlled spalling roof and provided <br />additional bearing to the roof. <br />PR -4 -3- 06/10 <br />1/(3/11 <br />