2008-06-17_PERMIT FILE - C1981018A (5)

Home Browse Search

® eleven holes (LW3-1 to LW3-11) were drilled in the longwall #3. Disturbance of the archaeological site 5R6859 was mitigated. Hole LW3-12 in the longwall #3 and holes LW4-1 to LW4-13 in longwall #4 were drilled in 1990. Holes LW4-14 to LW4-17 and LW5-1 to LW5-17 were drilled in 1991. Holes LW5-8 to LW5-15 and LW6-1 to LW6-3 were drilled during 1992. Vent holes LW6-4 to LW6-12 and LW7-3 to LW7-5 were drilled during 1993. Holes LW7-6, LW7-8, LW7-10, LW8-2, LW8-3 and LW8-5 were drilled in 1994. LW7-1 and LW7-2 were permitted but not drilled because of the change in the start line location for LW-7. Holes LW7-7, LW7-9, LW8-1, LW8-4 and LW8-6 were permitted but not drilled. On January 31, 1996, the mine caught fire near LW-9 face. Emergency holes LW9-1 and LW9-2 were drilled to inject CO2. The working districts were eventually sealed. Drill hole LW9-3 was drilled to monitor mine gases and assess the fire condition. Vent hole LW10-1 through LW10-7 were drilled in 1997, LW11-1 to LW11-4 in 1997, LW11-6, LW12-1, LW12-3, and LW12-5 in 1998, LW67-1 thru LW67-4 in 2005, LW68-2 and LWB8-3 in 2007, and LWB10-1 thru LW610-4 in 2008. Degasification holes are utilized as necessary to ventilate longwall gob gasses from active panels and mining districts. In 2007 a spontaneous combustion event forced extensive drilling to locate and control the resulting fire. Nineteen drill holes on eighteen drill pads were constructed to address this issue (SC-xxxx holes). A nitrogen generating unit with compressors was installed at RDH-3 with a surface pipeline (6900') strung to SC-HG20, SC-HG26, and SC-HG33. This equipment is skid mounted enabling easy mobility. Nitrogen is injected to help keep oxygen out of mined out areas. Drill locations are shown on Map 147. Accesses to the locations are along existing roads and by cross country access with minimal blade work only where necessary. The two-track access to LW2-1 from LW2-2, is about 1/2-mile long. Part of the track is constructed around the side of a hill necessitating approximately 60 feet of the track to have a cut ranging up to 6 feet deep. The track width is maintained around 12 feet. The only disturbance of any significance was for the cut to be made on the side of the hill. Some rock blasting was required. An 18-inch culvert was installed on the access road to well LW2-1. The drill sites are about 100' x 100'. A site is formed by first salvaging available topsoil. The topsoil is stockpiled at one end of the drill site. Additional earthwork is minimized since the drill sites are usually relatively flat. A temporary mud pit is constructed next to the drill site. All suitable topsoil material is salvaged from the mud pit areas and placed in the topsoil stockpile. The mud pits are about 20' x 10' x 6'. Any runoff water and/or water/drilling mud mixture is generally collected in the mud pit. The mud pits effectively serve as the sediment control structures for the disturbance during drilling. Sediment control of the drill pad areas is achieved by Technical Revision #66 (2/2008) III-2 7