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SPRING 2013 SUBSIDENCE AND GEOLOGIC FIELD OBSERVATIONS <br />SOUTH OF DIVIDE AND DRY FORK MINING AREAS (E -SEAM) <br />1.0 SUMMARY OF FINDINGS <br />On June 13 and 14, 2013, Wright Water Engineers, Inc. (WWE) observed subsidence and geologic <br />field conditions of the South of Divide (SOD) and Dry Fork mining areas (consistent with current <br />Exhibit 60E) for Mountain Coal Company, LLC (MCC). Similar observations have been made <br />annually since 1996 and semi - annually since 2007 as a means to assess potential longwall mining <br />effects on the environment. <br />Efforts have been made recently to reduce the size of these semi - annual reports by eliminating <br />much of the background and historical information (e.g., subsidence projections) included in <br />previous reports. Specific details about subsidence projections can be found in Section 1.0 of the <br />Spring 2011 Subsidence Report and in Exhibit 60 and 60E of the West Elk Mine permit. <br />Additional background information, such as field recognition of subsidence and non - subsidence <br />features, can also be found in the Spring 2011 Subsidence Report (Section 2.0). <br />Based on field observations from 1996 to spring 2013, the effects of longwall mining above the <br />West Elk Mine have been less than initially projected as reported in Exhibit 60 (Dunrud, 1998 <br />rev.) and 60E (WWE, 2012). To date, mining effects on rockfalls or landslides have not been <br />observed in the Apache Rocks mining area. Sporadic rockfalls and landslides have been observed <br />in the Box Canyon mining area since 2006 where the steep, upper reaches of Sylvester Gulch and <br />Box Canyon abut West Flatiron. Since 2009, the area has stabilized somewhat as the mining - <br />related activities in this area have been completed. Nonetheless, the potential for additional <br />rockfall activity on the west- and east - facing cliffs of West Flatiron remains moderate to high as <br />was the case prior to mining. <br />Subsidence - related tension cracks were observed during our spring 2013 field visit to the SOD and <br />Dry Fork mining areas along some drilling roads accessed by US Forest Service Road 711 (Dry <br />Fork Road) and on methane drainage well (MDW) pads, particularly where they exist above active <br />831 - 032.795 Wright Water Engineers, Inc. Page 1 <br />September 2013 <br />