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Fall 2010 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />• In the South of Divide mining area, subsidence related cracks had previously been reported in <br />recently undermined drill pads for methane drainage wells (MDWs) E1-19, E1-15, E1-11.5 and <br />E1-8, as well as in Horse Gulch Road near the west end of E-seam Longwall Panel E1. At the <br />time of our fall 2010 field traverses, the observed subsidence cracks in the Horse Gulch Road had <br />healed and sealed to the point of non-recognition while some evidence remained in the cut banks <br />above the road in a few locations. Cracks were still visible in the road connecting the E1-8 and <br />E1-11.5 MDW pads although considerable healing of these areas had also occurred. In addition, <br />baseline observations were made of several new MDW pads above unmined portions of E-seam <br />Longwall Panels E2 and E3 in the South of Divide mining area. Several of these pads were <br />observed to contain differential settlement cracks associated with the largest fill areas of the pad <br />(likely due to ongoing settlement of inadequately compacted material). Details and examples of <br />this phenomenon can be found in the Spring 2010 Subsidence Report. Additional details <br />regarding the South of Divide mining area observations can be found in Section 3.0 of this <br />report. <br />• <br />831-032.792 Wright Water Engineers, Inc. Page 4 <br />April 2011