2009-04-29_PERMIT FILE - C1982056A (8)

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Water from the sump currently discharges to the lORT/FCM-2 Transfer Pipeline, with the potential to tie-in an fl- inch HPDE line to treatment ponds at some future time. Potential Future Treatment Installation -Each of the two planned treatment onds would be a roxim. p pp ately 170 x 85 x 8 feet, within an area of approximately 300 x 250 feet. The design for the treatment ponds is presented in Exhibit 8C(1), EMD Treatment Pond Design. Approximately 5,550 cy of topsoil would be salvaged and stockpiled adjacent to this pond area. As shown in Figure 1, Exhibit 8C(1), the existing light-use road would be extended to the treatment ponds, forming a loop. Approximately 740 cy of topsoil would be salvaged from the short segment of road connecting the treatment ponds, windrowed to the side of the road, and seeded with the topsoil stockpile stabilization seed mixture. Prior to discharging to the ponds, the discharge water would be treated using similar methods to those used at the Fish Creek Dewatering site to aid in settling of suspended and dissolved materials. A piping manifold or fittings and valves would allow selective discharge to the ponds to maximize their use and efficiency. An interior line between the two ponds would allow for flow between the ponds. A 15-foot wide road would encircle the ponds to provide for maintenance and repairs. An 8-inch discharge line buried approximately 4 feet deep would carry the discharge to Foidel Creek. A flow measuring device would be used to obtain the appropriate flow measurements. A 10 x 15 x 30 foot building would house the treatment system and control panels for the dewatering pump. The building would be constructed on a 10 x 3 x 0.5 foot concrete pad, as shown on Maps 17 and 18. Sediment control for the site would consist of seeding and (if necessary) mulching the topsoil stockpiles and cut and fill slopes, and use of an adjacent established vegetative filter. The SAE demonstration for this area is presented in Exhibit 8C, EMD Dewatering Treatment Facility. lORT Mine Dewatering Well No 2 (MR08-228 MR08-2301 • In order to both supplement the existing mine dewatering/mine water supply capacity of the IORT Mine Dewatering Well No. 1, and to provide back-up pumping capabilities for the EMD, TCC will complete a second mine dewatering well and install associated ancillary equipment and facilities at the current l ORT Mine Dewatering Well location. Completion of the new mine dewatering well, l ORT Mine Dewatering Well No. 2, will involve: • Modification of the existing ASC drainage controls at the IORT location, stripping and si;ockpiling of approximately 240 cy of soil material to accommodate expansion of the existing pad area • Extension of the existing pad area through grading and controlled placement and compaction of approximately 350 cy of select fill materials • Drilling and casing of a 12-inch diameter borehole approximately 1,360 feet to intersect the sealed and flooded EMD mine workings, and installation of a protected well-head and access manhole • Construction of a 1,000 foot 12-inch HDPE pipeline to connect to the existing IORT/FCM-2 Transfer Pipeline, and installation of appropriate control valves to allow routing of the mine discharge water to either the Barricade Chamber/FCM-2 location or to the 6MN Mine Water Storage Reservoir • Extension of a new overhead powerline from Substation 11 to the l ORT facilities using the existing poles and 5 new poles, and installation of a new transformer on a small concrete pad at the l ORT facilities • Construction/installation of associated ancillary control and monitoring equipment The incremental surface disturbance associated with expansion of the l ORT pad area will be less tha~i 0.20 acres. All other activities will occur within existing disturbance areas. The location and configuration of tb.e associated facilities modifications are shown on the Surface Facilities and Freshwater Systems Map, Map 24, and Drawing EX49P-F 1. Modification of the existing ASC drainage controls will involve realignment of existing ditches and berms to accommodate the minor pad expansion. Recent inspections have indicated some minor siltation and erosion that has affected the effectiveness of existing drainage control structures, so TCC will take advantage of the opportunity to have equipment on-site to complete needed drainage structure maintenance. A conventional down-Yiole hammer MR08-230 2.05-50.5 11/20/08