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SubTerra, Inc. Peabody Twentymile Coal LLC 09/27/2014 <br />Foidel Creek Mine <br />Permit Revision for Longwall Mining in the Wolf Creek Seam - Subsidence Evaluation <br />20023). Permit Revision PR09 -08 provided a similar analysis for subsidence effects on Fish Creek as <br />it meandered above the Wadge seam's Western Mining District (SubTerra, Inc., 2009).. <br />We have made extensive use of these data and information in preparing this report; copies of <br />referenced studies can be made available on request. <br />1.2. Foidel Creek Mine Layout in the Wolf Creek Seam <br />Drawing 2 shows the planned layout of development entries covered under the current Permit <br />Revision. Nine hundred, eighty five feet (985 -feet) wide longwall panels will be developed and <br />mined on 1,210 -feet centers using the retreat mining method. Under this mining method, three <br />nominal twenty foot wide development entries will be mined on either side of each panel from the <br />southern end of the mine towards the north. The rigid /yield pillar combination used between each <br />longwall panel will nominally include a series of 134 -feet wide by 232 -feet long rigid pillars each <br />located adjacent to two 40 -feet wide, 107 -feet long yield pillars. <br />Twentymile Coal, LLC will mine an average height of 8.7 -feet in the Wolf Creek Seam which is located <br />between 110 and 170 -feet below the mined out Wadge Seam under a depth of cover ranging from <br />1,000 -feet at 1 -Right to 1,800 -feet at 9- Right. <br />The expected extraction ratio during development is less than 30% increasing to greater than 80% <br />during longwall mining. <br />1.3. Pre and Post Mining Land Uses <br />Land above the Foidel Creek Mine is primarily used for ranching and will continue to be used for <br />this purpose. The Union Pacific Railroad Spur, Fish Creek and Foidel Creek, and three power <br />lines also cross the area proposed for mining as noted above. <br />1.4. Potential Subsidence Impact Evaluation <br />We have evaluated potential subsidence impacts from longwall mining at the Foidel Creek Mine <br />according to Rule 2.05.6(6) — see Attachment A for full citation. The following sections of our <br />Report address these phenomena with regard to the requirements of Rule 2.05.6(6): <br />1. Section 3 — Evaluation of Potential Subsidence Impacts to the Railroad Track. <br />2. Section 4 — Evaluation of Potential Subsidence Impacts to Fish Creek and its AVF. <br />3. Section 5 — Evaluation of Potential Subsidence Impacts to Power Lines. <br />4. Section 6 — Evaluation of Potential Subsidence Impacts to Water Wells. <br />1.5. Closure <br />The enclosed and attached work products were prepared for Twentymile Coal, LLC as input to their <br />preliminary planning and permitting for development and extraction of the Wolf Creek Seam of the <br />Foidel Creek Mine project and for no other purpose. The work was performed under the Terms <br />and Conditions of our Contract with Peabody Twentymile Coal LLC and in a manner consistent <br />with the level of care and skill ordinarily exercised by other professional consultants in similar <br />circumstances at the time the Services were performed. No other warranty, express or implied is <br />made. <br />3 SubTerra, Inc_, 2002_ Twentymile Coal Company, AVF Subsidence Study, Project 2002 -06. <br />4 Subterra, Inc., 2009 Permit Revision PR09 -08 for the Foidel Creek Mine, April, 2009, Project 2009 -04. <br />2 PN: 2013 -26 <br />