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West Elk Mine • MCC has installed numerous pumps and miles of pipeline in the mine to manage inflows in . accordance with the mine water management schematic on Figure 22. Borehole lithologies and stratigraphic correlations, both locally and regionally, have been thoroughly scrutinized to assess whether there are indications of other fault systems. The result of this assessment has shown that there are as many as four known or inferred fault zones that may be encountered while mining the E Seam in the SOD permit revision area (see below). However, the known or inferred fault zones are nearly vertical in orientation and may be very difficult to identify from vertical borehole evaluation. • Water quality analyses from vazious surface and subsurface sources have been reviewed to assess similarities for purposes of "finger-printing" these fault inflows. Isotope analyses on samples obtained in November 1996 from the fault inflows, after a sustained period of constant 85± gpm inflow were also conducted for "finger-printing" and age-dating (residence time) purposes. These analyses indicate this water has been below the ground surface for an extended period of time. Tritium isotope analysis shows there to be no tritium within the samples for all practical purposes. This indicates that the water entered the subsurface prior to the detonation of nuclear explosives in the atmosphere (i.e., before 1943). Carbon dating suggests that the fault inflows are as much as 10,500 years old. Oxygen and hydrogen isotope ratio analyses were also conducted on fault inflows. The • results show a deviation from the ratios expected for meteoric waters in the Rocky Mountain region (i.e., the Meteoric Water Line). This deviation indicates a lack of direct communication or direct recharge from a surface water source. Additional water quality analyses have been conducted and compared with known water sources in the general vicinity of the mine to assess the potential source of the fault water and the potential impacts to the water resources of the area. These data indicate that the groundwater within these two fault systems discharge from hydraulically isolated systems even though the source has been determined to be a fractured groundwater reservoir within the Rollins Sandstone beneath the B Seam coal. Distribution systems within the mine have been and will be constructed to handle these lazge inflows, and to separate and dischazge the water to either the large capacity sumps or the surface. MCC has constructed pipelines and necessary pump stations in the entries developed north of the BEM Fault projection in the Box Canyon Mains. Water quality results indicate that the fault system water, like other inflows to the mine, is of sufficient quality to allow for direct dischazge to the North Fork. Other pipelines carry sediment-laden water to the NW or NE Panels sealed sumps or to surface ponds for treatment, if necessary, and release (or use). Evaluation of downgradient migration of water stored in these sealed sumps has been considered including evaluation of the sealed workings of the Sanborn Creek Mine (a B Seam mine on the north side of the North Fork that is no longer active). The very low permeability of the coal seams and surrounding Formations suggest that very limited downgradient movement of water from the sealed sump is likely. Projections of the BEM and 14HG fault systems show that, if they were to extend across the North Fork, they would not intersect any of the B Seam workings of that mine 2.05-1l3 Revised November 1004 PRl0