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<br />' Monitor hole 36-2U was mined past in a gateroad during August 1993. There are numerous drill <br />holes at this location and one hole was encountered during mining. The hole encountered <br />' underground is seeping at the measured rate of 0.25 gallons per minute. It is not known if the hole <br />mined through is one of the monitor holes (36-2U and 36-2L) or one of the exploration holes drilled <br />on this location. Between the last two readings during this monitoring period 36-2U showed a water <br />level drop of about two feet. <br />Monitor hole 35-4U readings were relatively stable during this monitoring period. Gateroad <br />development mining passed within about 350 feet of this hole in March 1993. This monitor hole is <br />within a longwall panel and will be mined through in 1994. Monitor hole 4-20U appears to have <br />stabilized. <br />' The data collected during this water year continues to demonstrate that there is very limited vertical <br />permeability between the upper and middle monitoring zones. <br />t The 'siltstone~oal facies' monitoring holes are designated by an 'M' following the hole number. <br />These monitor holes are open through the interval containing the D Seam which is currently being <br />' mined. <br />Monitor hole TW2-17M was by-passed by mining first in November 1985 but was not intercepted <br />in the workings. It is apparently located in a pillar completely surrounded by open workings. At that <br />time it showed virtually no response to room-and-pillar mining. In February 1988 longwall panel <br />1 was mined to within about 900 feet of this hole. Obviously, longwall mining disrupts the mined <br />zone more than room-and-pillar mining, and the water level in TW2-17M did show a response to <br />mining at that time. The water level showed a slight decline during this period. <br />Mining activity approached to within about 350 feet of 35-4M in March 1993. The water level in this <br />hole showed a drop of about 33 feet during the water year. Some decline would be expected with <br />' mining on three sides of this hole, however, the last two readings were essentially static. As noted <br />above, this location wilt be mined through as part of longwall panel 7 during 1994. <br />Hole 2-7M is apparently more sensitive to room-and-pillar mining. The water level in this hole has <br />' been dropping since mid-1987 when room-and-pillar mining approached to within about 700 feet. <br />This area was mined past in June 1988 and the water level has continued to drop, although no <br />' monitor holes were intercepted underground. In April 1990, LW3 was mined past this location. The <br />March 1990 water level had dropped beyond our measurement capability and remained so during <br />this monitoring period. Longwall panel 4 was mined past this location in August 1991. <br />1 <br /> <br />9 <br /> <br />