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Mayo and Associates, LC <br />~• <br />A <br /> <br /> <br /> <br /> <br />1 <br /> <br />pressure in the wells was only about 2 psi (i.e. ~ 5 feet of water) the test could not be <br />conducted. What the wells demonstrated was that the sandstone channel was not fully <br />saturated and it was a perched, unconfined groundwater system, Water issuing from the <br />channel had a mean14C age of 2,000 yeazs (Mayo and Associates, 2001). The perched, <br />unconfined groundwater system evaluated in the 6th West azea is consistent with the <br />commonly observed roof drip conditions. <br />3.2.2 Sandstone in the Mine Floor <br />Occasionally small amounts of groundwater have been observed to discharge from <br />sandstone underlying coal seams in Energy West's mines and other mines in the Wasatch <br />Plateau. However, in 1997 substantial groundwater inflows issued from the mine floor <br />in the Trail Mountain Mine (Mayo and Associates, 1997c). In the southern portion of the <br />mine, at the down plunge end of the Straight Canyon Syncline (Figure 10) the Hiawatha <br />Seam is located directly on the Spring Canyon Member. When the coal was removed <br />approximately 200 to 300 gpm of groundwater dischazged from mine floor. Mine floor <br />discharges continued until the Spring Canyon Member was depressurized. Depressuring <br />the Spring Canyon Member resulted in a water level decline in monitoring well TM-3 <br />from 64 psi {i.e., 150 feet above land surface) to -75 feet (Mayo and Associates, 2001). <br />TM-3 is completed in the Spring Canyon Member outside the mine at the down dip end <br />of the syncline. <br />Evaluation of Potenfial Groundwater Inflows 31 <br />Associated with E Seam Mining, <br />West Elk Mine, Somerset, Colorado <br />February 24, 2004 <br />