REP36913 - Laserfiche WebLink

Home Browse Search

• Wells 81-01 (Figure 6) and 83-01 (Figure 7) between 1988 and 1990 appear to have leveled off since the middle of 1990, and have recovered to initially monitored levels. Water levels in these two wells measured during 1997 are similar to the levels measured in the early eighties, though notable fluctuations has been observed at 81-01. The slight recovery from 1984 through 1988 is apparently the result of a shift in the location of mining to an area further up~iip. Water level fluctuations since 1983 are greater in Well 81-01 as compared to Wells TR-7A and 83-01 as would be expected since this well is closer to the location of mine dewatering. Water levels in well TR-7a (Figure 5) exhibited a decline during 1996, followed by a steady recovery through 1997. CEC will continue to monitor this trend. The water levels in Well 83-02 (Figure 8) show a different pattern. The water level decline of about 150 feet from 1987 to mid 1989 in • Well 83-02 is determined to be related to mine dewatering as Mine 5 workings approached the location of the well. The more abrupt 200 foot decline in water levels observed near the end of 1989 and beginning of 1990 is thought to be a drawdown response due to subsidence as its is located on only a few hundred feet horizontally from an F seam longwall panel which was mined in a similar time frame. The water level stabilized until 1994 when it recovered to the 1983 levels. Wells TRH and 83-03 are located at greater distance horizontally from the active operations for mines 5 and 6. Water levels in Well TRH (Figure 4) historically appear to be related to the fluctuations observed on all three of the downgradient Middle Sandstone Wells: 81-01, 83-01 and 83-02. During 1997, water level measurements at well TR-4 continued to stabilize, displaying smaller fluctuations. The water level decline in TR-4 prior to 1984 • L-81-094 1997AHR Page 3