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' The data collected during this water year continues to demonstrate that there is very limited vertical permeabiliiy between the upper and middle monitoring zones. ' The 'siltstone-coal facies' monitoring holes are designated by an 'M' following the hole number. ' These monitor holes are open through the interval containing the D Seam which is currently being mined. Monitor hole TW2-17M was by-passed by mining first in November 1985 but was not intercepted in the workings. It is apparently located in a pillar completely surrounded by open workings. At ' that time it showed virtually no response to room-and-pillar mining. In February 1988 longwall panel 1 was mined to within about 900 feet of this hole. Obviously, longwall mining disrupts the mined zone more than room-and-pillar mining, and the water level in TW2-17M did show a ' response to mining at that time. The water level showed a decline of approximately 15 feet during this period. ' As noted above, the 35-4M location is within LW-7 and was mined through in October 1994. The hole is venting air and has been capped. Hole 2-7M is apparently more sensitive to room-and-pillar mining. The water level in this hole had been dropping since mid-1987 when room-and-pillar mining approached to within about 700 ' feet. This area was mined past in June 1988 and the water level had continued to drop, although no monitor holes were intercepted underground. In April 1990, LW3 was mined past this location. The water level had dropped beyond our measurement capability from March 1990 through July 1994, however, the new equipment shows a dry blockage at 437 feet. Longwall panel 4 was mined past this location in August 1991. ' The hydrographs of the 'lower sandstone facies' are designated by the letter'L' following the hole ' number. The original hole 2-17L was plugged in early fall 1985 as it was feared the mine would intercept it. As it iurned out, the hole was never encountered in the workings. AS required by DMG, a new hole was drilled and completed in the 'lower sandstone facies'. From the time the ' new hole was completed, the water levels in this hole have fallen. During May 1986, mining in gate road 2nd East intercepted an exploration hole, (21012-9) that had been drilled in 1978. This hole had been plugged with heavy mud but leaked from both the mine roof and floor when the ' hole was intercepted. Water flow from the hole in the roof was about 3 gpm (gallons per minute) and was plugged with a packer. The flow from the hole in the floor was on the order of 1 gpm and ' was plugged by pumping an expanding grout into the hole. This exploration hole is located about 1500 feet from 2-17L and the leak in the floor may have reduced the piezometric pressure in the 'lower sandstone facies' at 2-17L During March of 1987, another exploration hole (21012-10) ' was intercepted by mining in gate road 3rd East. This hole also leaked at about the same rate ' 9 1