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Mayo and Associates, LC <br />1. EXECUTIVE SUMMARY <br />The potential for E Seam related groundwater inflows have been evaluated by <br />comparison with groundwater inflows associated with coal mining in similar geologic <br />and hydrogeologic conditions. The hydrogeologic conditions and causes of groundwater <br />inflows in five Utah coal mines as well as inflows in the Bowie, Oxbow and West Elk <br />Mines in Colorado have been evaluated. Mine groundwater inflows are largely <br />associated with inactive zone groundwater flow systems that have limited hydrologic <br />communication with near surface water. In the coal mines inactive zone inflowsltypically <br />occur as: <br />n <br />1. roof inflows from sandstone channels located in the lower portion of the <br />Mesaverde Group. Inflows from overlying sandstone channels issue from roof- <br />bolts holes, vertical borings, or channels which are exposed during mining, <br />2. floor inflows from shoreface and foreshore sandstones, and <br />3. damage zone inflows associated with faulting. Fault damage zone inflows <br />significantly increase inflow rates and volumes of floor inflows. In unusual <br />circumstances minor amounts of neaz surface (active zone) groundwater enters the <br />mine environment along fault damage zones. <br />Maximum groundwater inflow rates and durations of inflows for various mines are <br />shown in Table 1. <br />Evaluation of Potential Groundwater Inflows 5 February 24, 2004 <br />Associated with E Seam Mining, <br />West Elk Mine, Somerset, Colorado <br />