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<br />• Response: The reclamation plan discussion has been revised to reflect a concrete removal <br />depth of 3-feet consistent with typical shallow rooting depths in this area. Please see <br />accompanying revisions. <br />60. The rewriting of page 2.05-28 has a direct effect on page 2.05-29. Please make the necessary <br />corrections. <br />Response: Page 2.05-29 has been reviewed and revised as appropriate for consistency with <br />the preceding page as noted. Please see accompanying revisions. <br />2.05.4 Postminin~ Land Use <br />61. You state that "the road that extends up Elk Creek Canyon will" remain, yet in other areas of the <br />document and maps indications are of reclaiming the road. Please clarify this item. <br />Response: Please refer to previous Response 58 above. <br />2.05.6 Mitigation of the Impact of Minim Operations <br />2.05.6(3) Protection of the Hydrologic Balance. <br />62. One concern noted during the Division review of permit Revision No. 3, was that mining in <br />most of the Sanborn West Tract will be performed under old mine working. Thus, the potential <br />• existing for encountering significant mine water inflows. OCM has an existing plan for <br />handling, treating, and discharging mine water and has also committed to having standby <br />pumping capacity available to handle large mine inflows. prior to the proposed TR-29, OCM <br />utilized room and pillar mining methods. With the incorporation ojlongwall mining, does the <br />plan for handling and discharging mine water inflows remaining adequate? Does the potential <br />exist for encountering even greater inflows and possible saturating the face of the longwall as the <br />mine workings are collapsed due to the retreat of the longwall? <br />Response: Oxbow is currently mining in the 3rd North, 4th North, and 5th North entries <br />which underlie old E-Seam mine workings (refer to Map 5-044) which are believed to be <br />partially flooded. While some mine water inflow has occurred in all areas, including the <br />current working areas, significant increases in inflow rates have not occurred as mining has <br />progressed under these old workings. Given that subsidence from existing operations has <br />not resulted in significant drainage from the overlying workings, it is believed that the <br />combination of relatively strong intervening strata and depth below the existing workings <br />may limit drainage due to subsidence fracturing regardless of mining method. Potential <br />mine water inflows from the old workings would also be limited by the finite storage <br />capacity of the old workings and the limited likelihood of unrestricted flow paths. <br />Oxbow plans to proceed with longwall development and operations with the assumption <br />that mine water inflow will not increase significantly over current inflow rates. Given <br />Oxbow's concern relative to employee safety and a significant investment in the longwall <br />system, the planned development would not proceed if available information indicated a <br />reasonable potential for flooding. During longwall development and initial operations <br />• Oxbow will, however, carefully monitor mine inflow rates to provide for early <br />identification of any significant changes in inflow rates. If significant changes ~n inflow <br />rates are indicated by this monitoring, Oxbow will proceed with modification of the <br />existing plans for handling, treatment, and discharge of mine water and will submit revised <br />plans to the DMG as a Minor Revision for review and approval. <br />