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Mayo and Associates, LC <br />I • <br />lease area extracted coal from the Lower O'Connor A Seam (LOA). All of Mine 3 is <br />located on the north flank of an anticline where the coal seams dip about 7° to the <br />northwest. In the western portion of the mine area the Storrs Member separates the <br />LOA and the Flat Canyon Seams, however, the Storrs Member pinches out and the two <br />seams merge in the eastern portion of the mine. In Mine 2 coal is mined from the LOA <br />Seam (Figure 3). <br />Groundwater entered the mine through three pathways (Mayo and Associates, 1994, <br />1996b; Hydrologic Consultants, lnc, 2002; Canyon Fuel Company, 2002): <br />1. roof inflows from sandstone channels in the Blackhawk Formation, <br />2. floor seeps, presumably from the Storrs Member of the Star Point Sandstone, and <br />~• <br />~• <br />J <br />3. fault-related damage zones associated with Joes Va]]ey Fault. <br />3.5.1 Sandstone Channels and Floor Seeps <br />Prior to January 1999 the average groundwater inflow into Skyline mine was <br />approximately 350 gpm (Canyon Fuel Company, 2002). This water discharged from <br />sandstone channels as roof drips and as floor seeps (Mayo and Associates, 1994, 1996b). <br />Most of the water issued from roof fractures and roof boltholes. A two to three foot high <br />damp band of calcite wall dust, wetted by capillary action was common, suggesting that <br />some water leaked from the mine floor from an underlying groundwater system. Roof <br />drip waters have 14C ages of 2,500 to 10,500 years and contain essentially no 3H (Mayo <br />and Associates, 1996b). <br />Evaluation of Potential Groundwater Inflows <br />Associated with E Seam Mining, <br />West Elk Mine, Somerset, Colorado <br />46 <br />February 24, 2004 <br />