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West Elk Mine <br />Imported water from the North Fork = 436 AF (270 gpm) <br />Miscellaneous groundwater inflows = 52 AF (30 gpm) <br />BEM and 14HG fault inflows = 129 AF (80 gpm) <br />Mine OutRows <br />There aze numerous ways for water to leave the mine. Mine outflows could consist of the <br />following: water pumped from a sump in the mine to the sedimentation ponds, direct dischazge <br />of fault water, direct discharge of F Seam colluvial water, dischazge from the sealed panels <br />sumps, to Lone Pine Gulch, and/or to Sylvester Gulch, minor groundwater seepage from the <br />sealed panels sumps, water retained in the product and gob, and miscellaneous losses. <br />Historically, the water pumped to Ponds MB-1 and MB-2R and water retained in the product and <br />gob have been the most significant mine outflows. With the fault inflows, discharges from the <br />sealed panels sumps to Sylvester Gulch has become the dominant pathway for mine water <br />outflows. <br />As a result of pumping water into the NW Panels sealed sump (and eventually the NE and Box <br />Canyon Panels sealed sumps), minor groundwater seepage through the unmined coal from the <br />down-dip (north) ends of the panels could potentially occur. The Groundwater Quantity section <br />• demonstrates that the calculated "worst case" amount of water (with the sealed sump at full <br />capacity) leaving the NW Panels sealed sump would be 0.7 to 8.4 gpm. Importantly, the actual <br />sump outflow rate is defined to be perhaps less that the lowest calculated rate of 0.7 gpm per <br />MCC's actual experiences. These include the relatively dry mining faces immediately prior to <br />the high pressure fault inflows, and most importantly, in eazly 1998, after drilling the NW Sump <br />#1 horizontal drill hole 215 feet, the first water was encountered just 17 feet from the filled <br />sealed sump (with approximately 65 feet of water head). <br />In Mine StoraPe <br />The Groundwater Quantity section discusses the use of the mined NW, NE, and Box Canyon <br />Panels for water storage. The NW Panels sealed sump became especially important when <br />development mining intercepted the 14HG Fault inflow in January 1997. <br />Beginning in August 2000, a new mine water pumping facility located in Sylvester Gulch <br />began discharging to the surface on a consistent basis, in full compliance with the NPDES <br />permit limitations. By January 2001, the mine was discharging about thirty percent of the <br />time and at a rate of as much as 1,800 gpm. By the spring of 2001, all water stored in the <br />NW sealed sump was removed allowing this storage area to be potentially available should <br />large additional inflows occur within the mine. Presently, all mine water runoff and <br />inflows are collected, conveyed to the NE Panels sealed sump, and then pumped from the <br />mine for discharge to Sylvester Gulch through this water pumping facility. <br /> <br />2.05-117 Revised November 1004 PRIG; Rev. March 1006; Rev. May 2006 PRIO <br />