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SubTerra, Inc. Peabody Twentymile Coal, LLC 03/16/2015 <br />Foidel Creek Mine <br />Permit Revision for Longwall Mining in the Wolf Creek Seam - Subsidence Evaluation <br />5.3.3. Increase in Middle Creek's Surface Area <br />Middle Creek will only be marginally affected by mining in the Wolf Creek seam with no anticipated <br />increase in its surface area. <br />5.3.4. Potential for Fissure Development and Water Loss (or Stream Pirating) <br />Surface cracking or fissuring has previously been confined to areas where the Twentymile sandstone <br />either outcrops or is located relatively close to the surface. In these areas, the blocky nature of the <br />Twentymile sandstone may result in strain concentration at joints, abnormal displacement between <br />adjacent blocks and surface cracking. <br />The combination of a maximum predicted tensile strain of +0.005 and relatively thick cover of marine <br />shale over the Twentymile sandstone in the study area will decrease the potential for surface cracking <br />or fissuring. The potential for water loss under these conditions is extremely low. <br />In addition, no evidence of "stream pirating" has been observed during extensive undermining of Fish <br />Creek and Foidel Creek and their AVF by Panels in the Wadge Seam in the Northern Mining District. <br />5.4. Monitoring Requirements <br />Visual inspection and conventional or GPS surveys of the undermined Fish Creek areas may be used <br />to confirm the predicted effects of mining. This methodology has previously been successfully used in <br />the Eastern and Northern Mining District at the Foidel Creek Mine's Wadge seam. <br />12 PN: 2013-26 <br />