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above the 6-Main North entries. Drilling of the borehole was covered by the TROS-48 submittal. Details <br />for the concrete pad and bulk storage and transfer facilities will be submitted for review and approval as a <br />Minor Revision, prior to installation. <br />The water component includes construction of a reinforced concrete pad and footers, installation of a water <br />,tank and associated pumping installation, and drilling of a nominal 13-inch borehole from the surface to <br />the underground workings from the shaft pad above the 6-North Main entries. Drilling of the borehole was <br />covered by the TROS-48 submittal. TCC constructed a steel water tank 85 feet in diameter and 24 feet high <br />designed to hold one million gallons. The tank rests on areinforced-concrete foundation consisting of a <br />spread-footer, stem wall, and slab floor supported by concrete pilings. Preparation of the tank foundation <br />area involved grading, compaction, and excavation for the support pilings and spread footer. Following <br />site preparation, the reinforced concrete pilings and footers were formed, and poured, folJbwed by the <br />reinforced concrete pad and stem wall. The steel tank was fabricated in sections which were theh placed <br />end anchored on the stem wall. A water-tight liner system completed the tank installation'. <br />A buried 8-inch HDPE line connects the tank to the water borehole for both filling from and discharge to <br />the mine water system. Pumps (both underground and at the surface) and control sensors and valuing <br />allow for controlled flow in either direction in the supply system. Tank fill sensors and a monitored <br />overflow drain were installed in the tank to prevent overfilling. The overflow drain line was installed in <br />the same trench as the water supply and return line and drains back to the mine-water handling system. A <br />small 8 x 8 foot pumphouse, was constructed next to the tank on a concrete foundation to house pumps and <br />valves. Power and/or control communications were laid in conduit above the waterline connecting the tank <br />and the borehole. <br />The locations for [he seven boreholes for project utility components are shown on Maps EX16E-M1 and <br />M2. As shown on Map 23, additional entries will be driven to the south of the 6 North Main entries to <br />connect with the ventilation shaft. These entries will be needed to maximize the efficiency of the <br />ventilation system. The entries will be driven in the same manner as is used in TCC's development work, <br />• <br />MR06-212 2.05 - 45.6f 10/31/06 <br />