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MR21-319 2.05 – 45.33 07/27/21 <br />As shown on Figure EX49EE-F1, TC has identified two potential borehole locations, although only one location will <br />ultimately be developed and completed. The drill pad size would be the same, regardless of location, and TC will <br />permit and bond for the maximum road disturbance. Road and pad construction will involve placement of <br />construction sediment controls, soil recovery, installation of drainage features, any necessary cut/fill work to establish <br />the road profile and pad, and placement and compaction of approximately 3 inches of suitable road-base materials <br />and 8 inches of pit-run gravel for the road, and gravel surfacing on the pad. The 24-foot wide road surface will be <br />graded and crowned to promote effective drainage. The total road disturbance will be approximately 1.6 acres, and <br />the maximum pad disturbance (including cut/fill slopes and diversion ditches) will be approximately 2.3 acres. <br /> <br />The proposed pad and road locations are on a low-gradient sidehill, so upgradient drainage will be limited. The <br />limited amount of drainage from upgradient areas will be routed under the road through culverts or intercepted and <br />routed around the borehole pad by a small perimeter diversion ditch on the east, south, and west sides of the pad, <br />utilizing small rock-lined sediment traps to control discharge and sediment. Drainage from the borehole pad areas <br />will be controlled under a Small-Area Exemption, with gravel surfacing on the pad and road to control runoff and <br />sediment, stabilization of cut/fill areas with temporary revegetation seeding, control of runoff from outslope areas for <br />the original by the perimeter ditch and sediment traps, and control of drainage from the new pad by the existing down- <br />gradient control features (wattles of equivalent). Drainage designs for the culverts and diversion ditch are provided <br />in Exhibit EX49EE. <br /> <br />Borehole completion will involve drilling, installing, and grouting steel surface casing in place to a maximum depth <br />of approximately 60 feet (dependent on the ground conditions encountered). The boreholes will then be advanced, <br />to depth to intercept the Wolf Creek mine workings (original boreholes) and Wadge mine workings (additional <br />boreholes). Water, drilling fluids, and cuttings will be contained within one or more excavated pits or portable steel <br />tanks (porta-pits) on the borehole pad. For the original boreholes, the surface casing for the larger utility borehole <br />will be 32-inches in diameter. If dry, this borehole will be drilled to 22-inches and cased to 16-inches, or if wet, 30- <br />inches and cased to 24-inches. The surface casing for the smaller utility borehole will be 24-inches. The smaller <br />utility borehole will be drilled to 22-inches and cased to 16-inches if wet. If dry, this borehole will be drilled to <br />13.75-inches. A 6.675-inch and 3.5-inch carrier pipe will be placed and grouted in either the 16-inch casing (wet) or <br />13.75-inch (dry) borehole. The larger carrier pipe may be used for grouting, material transfer, or other utility needs. <br />The smaller carrier pipe may be used as a power drop or for a communications line(s). The two additional boreholes <br />will be drilled to a maximum diameter of 18-inches and a maximum depth of 990-feet and cased to a maximum <br />diameter of 14-inches. <br /> <br />Power to the 9-East Utility Borehole Installation will be provided by a branch-line from the existing nearby powerline, <br />extending from 990 to 1,700 feet, depending on which pad location is selected. Powerline construction will require <br />placement of from 14 to 34 power-poles, dependent on which pad location is selected and power-pole spacing (50 to <br />75 feet). A switch and transformer on the Yampa valley Electric line at the connection with the branch-line, and a <br />drop-line at the pad location will provide power to the portable skid-mounted exhauster units on the original pad and <br />up to two wheel-mounted exhausters on the new boreholes. Power for the two additional boreholes will be provided <br />by a drop-line on the existing pad and by a short (approximately 500-foot w/a maximum of two poles) extension from <br />the existing line for the new pad. The 9-East Utility Borehole Installation will remain in place until it is no longer <br />needed to support ongoing operations (estimated life of approximately 3-years) and will then be reclaimed. <br />Reclamation will involve plugging and sealing the boreholes, removing the powerline, re-grading the pads and road, <br />drainage reestablishment, soil material replacement, and reseeding. <br /> <br /> <br />7 East Cross Entries Cement Borehole (TR21-97) <br /> <br />In 2019 the 7 east cross entries were mined by the continuous miner in order to increase the rate of development of the 7 <br />East entries and allow two continuous miner sections to be mining simultaneously. In 2022 the long wall will mine <br />through the 7 East cross entries. For the safety of the mine and to protect the long wall equipment TC will fill the cross <br />entries with cement grout that is similar in strength and hardness to that of the coal seam. In order to pump grout in to <br />the cross entries a borehole from the surface will be drilled . The borehole pad site will be located off the 6MN road <br />prior to the NW Mains Fan site on the south east side of Foidel Creek. The pad site will be approximately 300’ x 300’ <br />and approximately 12” of topsoil will be salvaged, seeded and stockpiled adjacent to the pad location to be used for <br />reclamation. Refer to Exhibit 49FF.