2016-02-25_PERMIT FILE - C1982056A (6)

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SubTerra, Inc. Peabody Twentymile Coal, LLC 03/16/2015 Foidel Creek Mine Permit Revision for Longwall Mining in the Wolf Creek Seam - Subsidence Evaluation 20023). Permit Revision PR09-08 provided a similar analysis for subsidence effects on Fish Creek as it meandered above the Wadge seam's Western Mining District (SubTerra, Inc., 20094). We have made extensive use of these data and information in preparing this report; copies of referenced studies can be made available on request. 1.2. Foidel Creek Mine Layout in the Wolf Creek Seam Drawing 2 shows the planned layout of development entries covered under the current Permit Revision. Nine hundred, eighty five feet (985 -feet) wide longwall panels will be developed and mined on 1,210 -feet centers using the retreat mining method. Under this mining method, three nominal twenty foot wide development entries will be mined on either side of each panel from the southern end of the mine towards the north. Twentymile Coal, LLC will mine an average height of 9 -feet in the Wolf Creek Seam which is located between 100 and 170 -feet below the mined out Wadge Seam under a depth of cover ranging from 900 -feet at 1 -East to 1,800 -feet at 14 -East. The expected extraction ratio during development is less than 30% increasing to greater than 80% during longwall mining. 1.3. Pre and Post Mining Land Uses Land above the Foidel Creek Mine is primarily rangeland used for livestock grazing and wildlife habitat and will continue to be used for this purpose. The Union Pacific Railroad Spur, County Road 33, Fish Creek, Foidel Creek and Middle Creek, and three power lines also cross the area proposed for mining as noted above. 1.4. Potential Subsidence Impact Evaluation We have evaluated potential subsidence impacts from longwall mining at the Foidel Creek Mine according to Rule 2.05.6(6) — see Attachment A for full citation. The following sections of our Report address these phenomena with regard to the requirements of Rule 2.05.6(6): 1. Section 3 — Evaluation of Potential Subsidence Impacts to the Railroad Track. 2. Section 4 — Evaluation of Potential Subsidence Impacts to County Road 33. 3. Section 5 — Evaluation of Potential Subsidence Impacts to Fish, Foidel, and Middle Creeks and their AVFs. 4. Section 6 — Evaluation of Potential Subsidence Impacts to Power Lines. 5. Section 7 — Evaluation of Potential Subsidence Impacts to Water Wells. 1.5. Closure The enclosed and attached work products were prepared for Twentymile Coal, LLC as input to their preliminary planning and permitting for development and extraction of the Wolf Creek Seam of the Foidel Creek Mine project and for no other purpose. The work was performed under the Terms and Conditions of our Contract with Peabody Twentymile Coal, LLC and in a manner consistent with the level of care and skill ordinarily exercised by other professional consultants in similar circumstances at the time the Services were performed. No other warranty, express or implied is made. 3 SubTerra, Inc., 2002. Twentymile Coal Company, AVF Subsidence Study, Project 2002-06. Subterra, Inc., 2009 Permit Revision PR09-08 for the Foidel Creek Mine, April, 2009, Project 2009-04. 2 PN: 2013-26