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P ea o 1111 ENERGY Twentymile Coal, LLC Jason Musick Colorado Division of Reclamation, Mining, and Safety 1313 Sherman Street, Room 215 Denver, Colorado 80203 (303) 866 -3567 X8134 RECEIVED Nov 0 6 2013 DMSION OF RECLAMATION MINING AND SAFETY 29515 Routt County Road 27 Oak Creek, CO 80467 970.879.3800 November 6, 2013 RE: Twentymile Coal, LLC - Foidel Creek Mine (Permit No. C -82 -056), Minor Revision (MR13 -270) 7 -Right Thickener Underflow Borehole and Pipeline Jason: Twentymile Coal, LLC (TC) requests CDRMS approval of a Minor Revision to our existing approved Permit for construction, operation, and reclamation of a new thickener underflow borehole, pipeline, and associated ancillary equipment and facilities at the 7 -Right (7RT) location. The new thickener underflow installation is needed to replace the existing 6RT Borehole, given that we have experienced some restriction of the underground flow -path for the tailings slurry, and a resultant rise in water levels in the associated portion of the abandoned and sealed 6RT mine workings. The 7RT Thickener Underflow Borehole installation will be located east of both the intersection of Routt County Roads 27 (RCR27) and 33 (RCR33) and the existing 6RT Borehole, on the north side of Foidel Creek and the Twentymile Mine railroad spur. The Thickener Underflow Borehole will extend approximately 850 feet from the surface into the sealed Eastern Mining District (EMD) mine workings. An existing pad area accessible from RCR33 will be used for completion of the borehole and installation of the required surface facilities, and a thickener underflow pipeline extension will be installed between the existing 6RT Borehole and the new 7RT Thickener Underflow Borehole. Installation of the 7RT Thickener Underflow Borehole will involve placement of construction erosion controls (silt fence and/or straw wattles), removal and stockpiling of soil materials and the limited vegetation from the existing pad area and road margins, minor fill placement (if necessary) and grading to establish a level drill pad, placement of gravel surfacing at the access point, excavation of a temporary cuttings pit on the drill pad, drilling and casing of the borehole, and installation of an access manhole. On completion of drilling and casing operations, the cuttings pit will be allowed to dry-out, material excavated from the pit will be replaced and graded, and the pad surface will be graveled to control erosion and sediment and provide an all- weather operating surface. The completed Thickener Underflow Borehole installation will include the access, a soil material stockpile; a 100 x 75 foot pad; the 6- to 8 -inch cased borehole, a 16 -inch cemented surface casing, and a covered 8 -foot diameter CMP culvert manhole with lightening protection. It is anticipated that due to timing and weather constraints, the initial pipeline installation may be on the surface, with the pipeline to be buried as weather permits or during the summer 2014 construction season. Pipeline installation will involve removal and windrowing of soil materials; trenching in most areas; placement of suitable bedding materials; placement, connection, and pressure testing of the pipeline; backfilling and compaction of suitable fill materials around and over the pipeline; backfilling