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Mountain Coal Company Exhibit 69 <br />West Elk Mine Sylvester Gulch Facilities <br />Mine Dewatering and Treatment Facilities Description <br />Sylvester Gulch Facilities Area <br />Introduction <br />Mountain Coal Company (MCC) proposes to construct new mine dewatering and <br />treatment facilities to be located at the existing dewatering boreholes site within the <br />Sylvester Gulch Facilities Area (SGFA). The treatment facilities will provide a method <br />of reducing total suspended solids (TSS) from the mine water, if necessary, and <br />discharge the water to the west fork of Sylvester Gulch in compliance with NPDES <br />discharge permit requirements. <br />The proposed facilities include a Dewatering Pump Station and Treatment Building, <br />Presedimentation Basin, Decant Return Basin and Pump Station, Sludge Drying <br />Lagoons, and Finishing Pond. Figure 1 illustrates the facilities plan. Figure 2 <br />illustrates the process flow diagram for the proposed facilities. <br />Treatment Objectives <br />Water quality analyses indicate that the mine dewatering and treatment facilities are <br />needed for suspended solids removal. The suspended solids generally consist of non- <br />hazardous and non-toxic clay particles and fine coal particles. Other pollutants and <br />parameters regulated by the NPDES permit, including organics and inorganics, are well <br />within the required limits. The suspended solids concentrations measured at various <br />locations in the mine range from 12 to 3,240 mg/L with an average concentration of <br />940 mg/L. The treatment facility has been designed for an influent suspended solids <br />concentration of 1,000 mg/L. The designed effluent TSS concentration will be less <br />than 25 mg/L, which provides a 20% safety factor to ensure compliance with the <br />NPDES effluent limitations. Due to highly variable flow conditions, the facility <br />designs require a certain level of flexibility and redundancy. To facilitate these <br />requirements, two treatment process trains, 1000 gallons per minute (gpm) each, will <br />be used. <br />Oct. 1997TR83; Revised Mav 199N MR143 <br />2 <br />