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The dewatering borehole site will consist of a 14-inch borehole, drill pad, pump and control building, powerlines, <br />and discharge line. The control building will be approximately 10 x 10 x 10 feet, and will be placed on a concrete <br />pad 10 x 10 x 0.5 feet. The drill pad will be approximately 100 x 200 feet within which two 10 x 10 x 50 foot mud <br />pits will be excavated. A 17.5-inch nominal diameter hole will be drilled into the sump area. Upon completion of <br />drilling, the mud pits will be backfilled with the excavated material. Approximately 1,350 feet of 14-inch metal <br />casing will be installed into the boring, and the annular space grouted. A submersible pump capable of pumping <br />350 gpm will be installed in the casing. Also, a transformer will be installed at the site to provide the required <br />power for the pumps. The transformer area will have a 7-foot high security chain-link fence placed around its <br />perimeter. A powerline, approximately 1.5 miles in length, will be constructed to tie this location into TCC's <br />power system. To complete the well installation, an 8-foot length of 8-foot diameter corrugated metal pipe with lid <br />will be place around the borehole. The material excavated from the 8-foot diameter pit will be spread over the pad. <br />The 6-inch riser pipe from the pump will exit the 14-inch casing, and a 90-degree elbow and associated valuing will <br />be attached for directing the discharge pipe into the 8-inch HPDE line going to the settling ponds. HDPE pipe is <br />extremely flexible. With a cold bend radius 160 inches, the pipe can be offset 80 inches vertically over a length of <br />160 inches. This greatly exceeds any potential offset due to surface subsidence. The piping to the ponds will be <br />buried to minimize freezing problems and will run approximately 4,800 feet to the treatment ponds. Power will be <br />brought into the pumps from TCC's existing powerlines. <br />Water from the sump will dischazge to two ponds, each approximately 170 x 85 x 8 feet, within an azea of <br />approximately 300 x 250 feet. The design for the treatment ponds is presented in Exhibit 8C(1), EMD Treatment <br />Pond Design. Approximately 5,550 cy of topsoil will be salvaged and stockpiled adjacent to this pond area. As <br />shown in Figure 1, Exhibit 8C(1), an access road (loop) will be constructed to the treatment ponds. Approximately <br />740 cy of topsoil will be salvaged from the short segments of road leading to the ponds. The topsoil will be <br />windrowed to the side of the road and seeded with the topsoil stockpile stabilization seed mixture. The topsoil <br />stockpiles will be stabilized with the topsoil stockpile stabilization seed mixture. <br />• Prior to dischazging into the ponds, the same chemicals used at the Fish Creek Dewatering borehole chemicals will <br />be added to aid in the settling of suspended and dissolved materials. TCC's experience indicates that use of these <br />chemicals to pre-treat the mine water in conjunction with settling ponds, is adequate to assure compliance with <br />applicable water quality standards. An inline static mixer will be used to distribute the chemicals throughout the <br />flow-stream prior to dischazge to the ponds. A piping manifold or fittings and valves will allow selective discharge <br />to the ponds to maximize their use and efficiency. An interior line between the two ponds will allow for flow <br />between the ponds. A 15-foot wide road will encircle the ponds to provide for maintenance and repairs. An 8-inch <br />dischazge line buried approximately 4 feet deep will carry the discharge to Foidel Creek. A flow measuring device <br />will be used to obtain the appropriate flow measurements. A 10 x 15 x 30 foot building will house the chemical <br />feed system and control panels for the dewatering pump. The building will be constructed on a 10 x 3' x 0.5 foot <br />concrete pad, as shown on Maps 17 and 18. <br />Sediment control for the site will consist of seeding and (if necessary) mulching the topsoil stockpiles and cut and <br />fill slopes, and use of an adjacent established vegetative filter. The SAE demonstration for this azea is presented in <br />Exhibit SC, EMD Dewatering Treatment Facility. <br />r1 <br />U <br />TR06-52 2.05-78 OS/] 6/06 <br />