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Peabod 1111 ENERGY Twentymile Coal, LLC 29515 Routt County Road 27 Oak Creek, CO 80467 970.879.3800 Mr. Jared Ebert June 17, 2015 Colorado Division of Reclamation, Mining and Safety 1313 Sherman St., Room 215 RECEIVED Denver, Colorado 80203 303.866.3567 X8120 JUN 19 2015 Re: Minor Revision MR15-288, 5 -Main North Water Pipelines Division of Reclamation, Mining & Safety Dear Mr. Ebert; With this submittal, Twentymile Coal, LLC (TC) is requesting CDRMS approval of a Minor Revision (MR15-288) to our existing approved Mining and Reclamation Permit, for conversion of the existing 5 -Main North (5MN) borehole to a dewatering borehole, and installation and operation of approximately 5,000 feet of buried water pipeline with vertical culvert access installations at five valve locations. The dewatering borehole, water transfer pipelines, and associated valving will allow water pumped from the Wolf Creek Reserve mine workings and the overlying accumulations of water in the sealed and abandoned Wadge Seam workings to be transferred to the existing 6 -Main North (6MN) Reservoir, the existing 10 -Right water pipeline, or the planned future passive mine water treatment system. It should be noted that the pump(s) for the Wolf Creek dewatering system will be installed and located underground in the mine workings, so no surface pumping installation or power will be required. In order to identify and prevent or minimize any potential environmental impacts associated with the proposed water transfer activities, TC reviewed the most recent grouse lek mapping and contracted a supplemental cultural resource survey for those areas not covered by previous survey work. These environmental analysis activities are documented by the cultural resource survey report and wildlife consultation letter, which are included with the PAP revision materials included in this submittal. The main 5MN Pipeline will connect to the 5MN Borehole riser, and extend approximately 3,200 feet to the west. Three "T's" and associated valving from this pipeline will allow routing of flows to the existing TORT Pipeline, the existing 6MN Reservoir, and the planned future passive mine water treatment system, as shown on Figure 1. The first lateral line will run approximately 620 feet from the main pipeline to the 6MN Pumphouse, and then extend another 500 feet to a "T' comlection on the TORT Pipeline. The second lateral line will extend approximately 190 feet to the inlet of the 6MN Reservoir. The third lateral line will be installed at some future date, and will be designed to tie-in to the planned passive water treatment system. All piping will be 10 -inch thermally fused High -Density Polyethylene (HDPE) pipe, and will be buried a minimum of 5 -feet deep so that it is below the normal 11VJ11111�. L'1 110 - out YCln1VtL1 C1:1P ciV lleJ:i l3� 111sta11.,U at thL 51V11V BLit Vl1u1L+ to plll MVV (.LVLI;JJ for maintenance and inspection, as shown on Figure 1. 8 -foot diameter CMP access risers will be installed at the four other pipeline junctions to protect the associated valves and provide inspection/maintenance access.