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As part of the 6MN Facilities project, TCC will establish a new pipeline running approximately 7,750 feet from the <br />10-Right Dewatering pipeline to the 6MN Million-Gallon Tank. The pipeline will be constructed of 10-inch HDPE <br />pipe, buried to a depth of approximately six feet, with one sub-grade crossing (bored under) of Fish Creek. Details <br />of the Fish Creek pipeline crossing are presented in Exhibit 490, 6MN Mine Water Storage Reservoir -Design <br />Drawings. Pipeline trenching operations will be conducted using atrack-hoe with the maximum working area <br />assumed to be 40 feet wide. Approximately 7 acres were disturbed in construction of the original water line, with <br />another 7.1 acres disturbed by the 6MN pipeline. Pipeline construction will involve removing and temporarily <br />windrowing soil materials along the edge of the pipeline corridor; trenching and temporary placement of the <br />excavated material on the opposite side of the trench; bedding, placement, connection, and testing of the pipeline; <br />controlled backfilling and compaction of the excavated material over the pipeline; and replacement, grading, and <br />reseeding of the soil material over pipeline disturbance areas. Access manholes may be established along the <br />pipeline route for inspection and maintenance purposes. Soil materials will be replaced following completion of <br />pipeline installation. Reseeding of the disturbed areas will be completed during the first appropriate planting period <br />following soil material replacement. <br />lORT Mine Dewaterin~ Well No 2 (MR08 228) <br />In order to both supplement the existing mine dewatering/mine water supply capacity of the TORT Mine <br />Dewatering Well No. 1, and to provide back-up pumping capabilities for the EMD, TCC proposes to complete a <br />second mine dewatering well and install associated ancillary equipment and facilities at the current TORT Mine <br />Dewatering Well location. Completion of the new mine dewatering well, IORT Mine Dewatering Well No. 2, will <br />involve: <br />• Modification of the existing ASC drainage controls at the lORT location, stripping and stockpiling of <br />approximately 240 cy of soil material to accommodate expansion of the existing pad area <br />• Extension of the existing pad area through grading and controlled placement and compaction of <br />approximately 350 cy of select fill materials <br />• Drilling and casing of a 12-inch diameter borehole approximately 1,360 feet to intersect the sealed and <br />flooded EMD mine workings, and installation of a protected well-head and access manhole <br />• Construction of a 1,000 foot 12-inch HDPE pipeline to connect to the existing Mine Water Return Line, <br />and installation of appropriate control valves to allow routing of the mine discharge water to either the <br />FCM-2 location or to the 6MN Mine Water Storage Reservoir <br />• Extension of a new overhead powerline from Substation 11 to the lORT facilities using the existing poles <br />and 5 new poles, and installation of a new transformer on a small concrete pad at the l ORT facilities <br />• Construction installation of associated ancillary control and monitoring equipment <br />The incremental surface disturbance associated with expansion of the lORT pad area will be less than 0.20 acres. <br />All other activities will occur within existing disturbance areas. The location and configuration of the associated <br />facilities modifications are shown on the Surface Facilities and Freshwater Systems Map, Map 24, and Drawing <br />EX49P-F 1. <br />Modification of the existing ASC drainage controls will involve realignment of existing ditches and berms to <br />accommodate the minor pad expansion. Recent inspections have indicated some minor siltation and erosion that <br />has affected the effectiveness of existing drainage control structures, so TCC will take advantage of the opportunity <br />to have equipment on-site to complete needed drainage structure maintenance. A conventional down-hole hammer <br />drill rig will be used to complete and case the No. 2 Well. It is anticipated that air or water will be used as the <br />primary circulation medium, with use of drilling mud only if required to maintain the integrity of the drillhole and <br />adequately flush drill cuttings. Cuttings and any drilling fluids will be retained in a portable cuttings pit. The No. 2 <br />Well will be cased with welded steel casing, which will extend to within 10 feet of the abandoned and flooded <br />EMD mine workings. The casing will be grouted in-place along its entire length, and a wellhead will be installed at <br />the surface from which the pump will hang. Alarge-diameter CMP culvert will be cemented in-place around the <br />well-head and fitted with a lockable cover. A multi-stage submersible pump will be installed in the well casing and <br />connected to a power controller in the existing well house. The new powerline from Substation 11 will replace <br />MR08-228 2.05-SSa 03/06/08 <br />