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Monitor holes 2-7U and TW2-7U are located on the same location. Although the water levels in the two holes have been comparable, fluctuations and trends in each hole have in the past been quite dissimilar. A longwall gateroad (4th East) was developed past this location in June 1988. No holes were encountered, however, there was wet ground in the area after mining. The area has since dried. Longwall panel 3 was mined past this location in April 1990. The next TW2-7U reading after that (6/21/90) showed a water level drop of almost 80 feet. The water level in 2-7U has, during this reporting period, shown a drop similar to, though of much smaller magnitude, that shown by TW2-7U during the previous period. After the drop, both holes exhibit the beginning of a rising trend which, if it continues during the next monitoring period, would indicate that equilibrium is reestablished much quicker after mining than was projected in the mining permit. Longwall panel 4 was mined past the location in August 1991, with no apparent response from either hole. The fact that these two holes completed in the same zone within a short distance of each other respond so differently further indicates the isolated nature of water bearing strata within the same zone. There are three other monitor holes at this same location, one in the upper zone and two in the lower. Monitor hole 36-2U showed a water level drop of about 5 feet between the December 1990 and February 1991 readings. ' Monitor hole 35-4U was relatively stable during this reporting period. Monitor hole 4-20U continues to display a slow declining trend. The data collected during this water year continues to demonstrate that there is very limited ' vertical permeability 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 Iongwall panel 1 was mined to within about 900 feet of this hole. Obviously, longwall mining disrupts the t 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 has shown a slow decline during this period. Mining activity has approached to within about 1200 feet of 35-4M. Between the first and third readings of this monitoring period the water level in this hole dropped about 23 feet. By the last ' reading the water level had risen over 11 feet. These changes are difficulat to attribute to mining at this time. Future monitoring will perhaps clarify the cause(s) of these changes. 9