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Mayo and Associates, LC <br />1 • Because 800 or more feet of overburden generally covers the sandstone channels, it is <br />~ unlikely that they have received appreciable rechazge by vertical infiltration from <br />overlying rocks or are in active hydraulic communication with either surface water or <br />near surface groundwater (Mayo and Associates, I999b). The most likely rechazge <br />locations are along up-dip regions in the vicinity of Minnesota Creek and possibly neaz <br />the contact with the Mt Gunnison intrusion. The structural orientations of the channels <br />~ adjacent to the intrusions are unknown. Because the intrusions aze lazgely laccolithic <br />' structures the dip of sedimentary sequences, including the channels, should bend upward <br />adjacent to the intrusions. Upturned bed adjacent to the intrusions would enhance <br />groundwater recharge. <br />Although saturation conditions of the sandstone channels have not been documented with <br />monitoring well data, appreciable quantities of water or unusual water pressures have not <br />been encountered in the numerous exploration bore holes that have penetrated the <br />' channels (Koontz, 2004 Personal Communication). If the channels are saturated and <br />hydraulic communication exists along much of the channel reaches, elevated water <br />' pressure should have been observed in the exploration drill holes. None-the-less, if the <br />channels are fully or almost fully water saturated, and have hydraulic communication <br />between the up-dip and down-dip reaches, appreciable groundwater could drain into the <br /> <br /> <br />1 <br /> <br />E Seam workings. The volume of water that could drain into mine workings becomes <br />progressively greater toward the northeast, <br />Evaluation of Potential Groundwater Inflows 60 <br />Associated with E Seam Mining, <br />West Elk Mine, Somerset, Colorado <br />February 24,2004 <br />