Laserfiche WebLink
LWB-8. This pillar was developed in September 2006. A substantial decrease in water <br />level was noted following the development work. <br />The water level in Hole 31-7M decrease by only 0.2 feet. This well is up gradient from <br />mining activity and the water level fluctuation is minimal. <br />Monitoring Hole 32-7M was plugged in August 2010 to eliminate connection with the <br />sealed off portion of the mine. <br />33-8M experienced a slight rise in water level of 1.3 feet, within the normally expected <br />range of fluctuation. <br />The hydrographs of the 'lower sandstone facies" are designated by the letter "L" following <br />the hole number. <br />Hole 2-17L showed a rise of 14.2 feet from the prior year. This rise is attributed to the rise <br />in water level within the D -seam workings. <br />Hole 4-20L showed a rise of 1.5 feet from the prior year. <br />Monitoring Hole 32-71- was plugged in February 2001 to eliminate connection with the <br />sealed off portion of the mine. <br />Hole 33-81- showed a 0.3 foot rise in the depth to water. This response is similar to the <br />adjacent 33-8M hole. <br />Monitoring hole 22-21- was completed in October 2005 for monitoring future mining <br />expansion. This hole recorded a 44.1 foot drop in the water table over the prior year. <br />This apparent fluctuation is difficult to explain since the nearest longwall mining is close to <br />a mile away and no other subsurface activity occurred recently in its vicinity. Other abrupt <br />changes in water level were observed at this well shortly following its construction (see <br />Appendix D-14). These fluctuations are most likely naturally occurring due to unique but <br />unexplained hydrogeologic characteristics unrelated to mining activity. <br />From the baseline data, all three zones should be classified as "aquitards" in that they will <br />yield water but at very slow rates. Mining in the B Seam so far has encountered only <br />small flows of water and the mine is essentially dry. Typical inflows are in the order of 20 <br />to 40 gpm (includes water resulting from leaks, water line brakes, and other similar <br />contributions as well as that originating from inflows from geologic formations) with <br />occasional short term increases when localized perched water tables are encountered. <br />