2013-09-27_REPORT - C1980007 (4)

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Spring 2013 Subsidence and Geologic Field Observations South of Divide and Dry Fork Mining Areas (E -Seam) Previously observed cracking at the MDW E3 -12 pad and along the drill road to the east were again visited and observed relative to subsidence cracks noted during the fall 2012 field visit. These cracks were again evident but showing signs of weathering and healing. These observations are included in the discussion below for Location 9. The MDW E3 -17.5 pad (Location 10) also continued to show subsidence - related cracks as noted in the Fall 2012 Subsidence Report but weathering had softened the edges and reduced their continuity and depth. Minor cracks were noted in the sandstone outcrop in the cut portion of the MDW E3 -21 pad but no subsidence features were evident on the MDW E3 -25 pad. 4.14.1 Location 8 Longwall mining occurred beneath the MDW E3 -6 pad after our fall 2012 field visit. As a result, our spring 2013 field observation represented the first post - longwall mining visit to this pad. This visit revealed several non - continuous but subparallel cracks trending approximately N10 °W through the pad. The longer of the cracks is apparent near where the road enters the pad from the southwest (Figure 16). This crack is non - continuous and approximately 40 feet in length with a maximum width of 3 inches and depth of 12 inches. The second crack follows the same general trend but is less continuous, better healed and terminates into the cut slope of the pad. A third subparallel crack is located on the southeast side of the pad and appears well - healed. This crack is evident on the pad over a length of about 20 feet. An apparent continuation of this crack occurs on the cut slope of the pad and above the cut slope toward the drill road (Figure 17). Regrading of the road has made it difficult to assess the extent to which the crack may have continued into or across the road. 831 - 032.795 Wright Water Engineers, Inc. Page 26 September 2013