2013-02-01_REPORT - C1981018 (2)

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The water level in Hole 30 -8M was confirmed dry at 464.5 feet. This is the same elevation as last year. The prior four years of measurements may have been showing residual water left in the casing. This well is located in a pillar next to the start line for LWB -8. This pillar was developed in September 2006. A substantial decrease in water level was noted following the development work. Hole 31 -7M decreased in water level 0.1 feet. This well is up gradient from mining activity and the water level fluctuation is minimal. Monitoring Hole 32 -7M was plugged in September 2010 to eliminate connection with the sealed off portion of the mine. 33 -8M experienced a slight rise in water level of 1.8 feet, within the normally expected range of fluctuation. The hydrographs of the "lower sandstone facies" are designated by the letter "L" following the hole number. Hole 2 -17L showed a rise of 28.5 feet from the prior year. This rise is attributed to the rise in water level within the D -seam workings. Hole 4 -20L showed a drop of 1.6 feet from the prior year. Hole 33 -8L showed a 1.2 foot rise in the depth to water. This response is similar to the adjacent 33 -8M hole. Monitoring hole 22 -2L was completed in October 2005 for monitoring future mining expansion. This hole recorded a 42.2 foot drop in the water table over the prior year. This apparent fluctuation is difficult to explain since the nearest longwall mining is over one mile away and no other subsurface activity occurred recently in its vicinity. Other abrupt changes in water level were observed at this well shortly following its construction (see Appendix D -15). These fluctuations are most likely naturally occurring due to unique but unexplained hydrogeologic characteristics unrelated to mining activity. From the baseline data, all three zones should be classified as "aquitards" in that they will yield water but at very slow rates. Mining in the B Seam so far has encountered only small flows of water and the mine is essentially dry. Typical inflows are in the order of 20 to 40 gpm (includes water resulting from leaks, water line brakes, and other similar contributions as well as that originating from inflows from geologic formations) with occasional short term increases when localized perched water tables are encountered.