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FALL 2015 SUBSIDENCE AND GEOLOGIC FIELD OBSERVATIONS <br />South of Divide and Dry Fork Mining Areas <br />1.0 INTRODUCTION <br />Beginning in the spring of 2007, Wright Water Engineers, Inc. (WWE) has conducted semi-annual <br />(spring and fall) field visits to the area over the West Elk Mine as operated by Mountain Coal <br />Company, LLC (MCC) to make subsidence and geologic observations. Prior to 2007, WWE <br />performed annual field visits dating back to 1996. Each of these visits provided observations <br />related to subsidence effects resulting from the longwall mining of coal in the B- and E -seams. <br />These observations have been subsequently chronicled in annual or semi-annual subsidence <br />reports. <br />This semi-annual subsidence report (Fall 2015 Report) is the second of two reports to be generated <br />based on observations made during the 2015 calendar year. In accordance with MCC's Colorado <br />Division of Reclamation, Mining, and Safety (CDRMS) permit, subsidence reports are to be <br />submitted by April 30 (for preceding fall monitoring) and September 30 (for preceding spring <br />monitoring). Spring observations are regularly hampered by limited access due to snow or muddy <br />conditions and fall observations are typically scheduled around the various hunting seasons. <br />Up until 2010, field observations represented more than 80 percent of the text contained within <br />each of the semi-annual subsidence reports. The remaining 20 percent was repeated reference text <br />provided for the convenience of the reader. As of the Fall 2010 Report, WWE and MCC began <br />an effort to reduce the size of the subsidence reports by removing repeated reference text. Each <br />fall report references the spring subsidence report for some information (e.g., traverse soil types, <br />thickness and sources, conclusions, and a bibliography) but does not repeat that same text. For a <br />summary of the subsidence prediction information contained in Exhibit 60 through 60E of the <br />current permit issued by the CDRMS, see Appendix A of the Spring 2015 Report. <br />831-032.797 Wright Water Engineers, Inc. Page 1 <br />March 2016 <br />