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Peabodq
<br />RECEIVED
<br />1111 ENERG
<br />Twentymile Coal, LLC
<br />MAY 17 2016
<br />29515 Routt County Road 27
<br />Division of Reclamation, Oak Creek, CO 80467
<br />Mining & Safety 970 879 3800
<br />Mr. Jared Ebert, Environmental Protection Specialist April 19, 2016 (Rev. May 12, 2016)
<br />Division of Reclamation, Mining, and Safety
<br />1313 Sherman Street, Room 215
<br />Denver, Colorado 80203
<br />(303) 866-3567 X 8120
<br />RE: Twentymile Coal, LLC - Foidel Creek Mine (Permit No. C-82-056), Minor Revision
<br />(MR16-296) — 9 -East Utility Borehole Installation
<br />Dear Mr. Ebert:
<br />Twentymile Coal, LLC (TC) requests CDRMS approval of a Minor Revision to our existing approved
<br />Permit for installation, operation, and reclamation of two boreholes, one 22 to 30 inches in diameter.
<br />and the second 13.75 to 22 inches in diameter to be located over the 9 -East Longwall Panel. The
<br />larger borehole, which will be cased and grouted to 24 to 32 inches OD, will be a monitoring and
<br />control borehole which will allow air to be drawn from the sealed mine areas by an exhauster unit.
<br />The smaller borehole, will be cased and grouted to 16 inches if water is encountered, otherwise two
<br />carrier pipes, 6.675 and 3.5 inches in diameter will be grouted in the borehole, with the larger carrier
<br />pipe to be a grout or utility pipe, and the smaller carrier pipe for a power drop or communication cable.
<br />The boreholes will extend to a maximum depth of approximately 1,090 feet, and will be accessed frorn
<br />County roads RCR33 and RCR179, using the existing established Fish Creek Tipple and 18 -Right
<br />Shaft roads. From the 18 -Right Shaft Road, a maximum of approximately 1,760 feet of new light -use
<br />road will be constructed to access the borehole location, as shown on Map 24, and in Exhibit 49EE,
<br />with up to four 24 -inch culverts installed along the road to pass natural drainage under the road.
<br />In addition to the new road construction road construction previously described, a new borehole pad
<br />(surface area approximately 200 x 200 ft.) will be constructed to support the initial borehole drilling,
<br />subsequent borehole completion activities, and any future site activities. As shown on Figure
<br />EX49EE-Fl, 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,
<br />and TC will permit and bond for the maximum road disturbance. The 9 -East Utility Borehole
<br />Installation will consist of the new light -use road, the new borehole pad; adjacent soil material
<br />stockpiles, two cased and grouted boreholes extending into the Wolf Creek Coal Seam mine workings,
<br />a surface blower installation, and a 1,700 foot (maximum length) powerline extension to provide
<br />power to the portable skid -mounted blower units. The proposed pad and light -use road locations are
<br />on a low -gradient side -hill, so upgradient drainage will be limited. The limited amount of drainage
<br />from upgradient areas will be intercepted and routed around the borehole pad by a perimeter diversion
<br />ditch with rock -lined sediment traps to collect and control run-on and discharge. Drainage from the
<br />borehole pad will be controlled under a Small -Area Exemption, with gravel surfacing on the pad and
<br />road to control runoff and sediment, and placement of rigid sediment filter material on the
<br />downgradient side of the soil material stockpiles. The 9 -East Utility Borehole Installation will remain
<br />in place until it is no longer needed to support ongoing operations, and will then be reclaimed.
<br />Reclamation will involve plugging and sealing the boreholes, regrading the pad and road, soil material
<br />replacement, and reseeding.
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