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f ~ • • Joseph J. Dudash January 24, 2000 Re: 1999 Ammal Subsidence Report Also during 1997, the area along the ridge between Hawksnest Creek and Bardine Canyon was mined, as well as the lower elevations of Hawksnest Creek in the azea of projected longwall panel number 1. The extreme eastem limit of mineable coal has been reached in these areas. Fourth, 5~', 6'", and 7'~ North were completed under the ridge. Pillars were extracted in 5'~ North. Sixth and 7'" North will become [he gate entries for longwall pastel number 2. Gate entries for longwall panel number t encountered the rock split in the coal that defines the eastem mining limit. Combined with the shortening of this panel by the mining limit, and the results of the longwall subsidence evaluation by Dr. John F. Abel, Jr., longwall panel number 1 will be mined by room and pillar methods. During 1498 development of longwall panel gate roads continued throughout the year. Due to mine ventilation conditions while waiting completion of the ventilation shaft, the eastem half of the mine was temporarily sealed, acid longwall panel development progressed in gate road entries of 18, 19, 20, and 21 North. Following completion of the ventilation shaft in July, the seals were breached and development was started in 8'" North. The longwall equipment was installed in the panel between 18 and 19 North, and longwall mining began on August 26, 1998. On August 31, September 8, September 14, September 21, September 29, October 5, October 12, November 1, and November 30 visual inspections directly above the active longwall panel between 18 and 19 North were made. No visual indication of subsidence was evident during any of the inspections. On November 1, a final visual inspection of the permit area from Elk Creek to Thompson Creek was made. No visible indication of recent mass movement was apparent and no new mass movement features were noted during the inspection. Due to a Mine fire, the Sanborn Creek Mine was closed from January 26, 1999 until May 1999. After to mine was reopened and cleattnp operations were completed, development of gate road entries for 19 % and 10 North commenced. Longwall operations started again in October to £nish the panel between 18 and l9 Nortlt. In early November the longwall was relocated to the panel between 20 and 21 North. Subsidence monitoring of the permit area was preformed during the monthly water monitoring. No visible indication of recent mass movement was apparent a~td no new mass movement features were noted during the inspection Sincerely, ~G~' ~~~~ Mark Milner Environmental Coordinator