2013-11-05_PERMIT FILE - C1981022A (2)

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SctYiat - 2.05.3 Information, was prepared to assess the potential problems associated with undermining the old workings. As a result of the recommendations presented in this report, muting in areas that are • under old workings known or suspected to be flooded will be: 1) Limited to 50 percent extraction; 2) Water from the old workings above will be drained prior to undermuung; or 3) It will he verified that the mine workings above are not flooded. At the discretion of mine management, standby pumping capacity maybe maintained in lieu of the noted protective measures. Coal from current and future mining operations will normally be routed to either the East Yard or Elk Creek coal stockpiles. The operator constructed the East Yard coal stockpile in 1992. The Ells Creek coal stockpile area has been constructed in phases. The fast phase, completed in 1995 - 1996, involved minimal site preparation and stockpiling of coal on the west side of the area. Tote second phase, which includes extension of the Elk Creek culvert; stripping of the lower canypn sidewalls to accommodate dead storage; relocation of the existing mine shop, warehouse, office, storage buildings, Substation No. 1, and a segment of the existing powerline; installation of a coal reclaim system; and construction of two stacking rubes along with associated transfer conveyors; was initialed in 1997 and completed in late-1998. The coal stockpile area neaz the tipple was decommissioned in 1992. The area azound the tipple is now agravel-surfaced pazking area artd yard. The haul road adjacent to the Sanborn Creek Mine overland conveyor may be used in an emergency or if the overland belt is shut down as a haul road to transport coal to the stockpiles or to reclaim coal from the East Yard stockpile. Elk Creek Mine -The Ells Creek Mme reserve area will be accessed by declines driven from portals located neaz the D Seam subcrop in Elk Creek Canyon. Site preparation activities for initial portal installation will involve culverting of two segments of Ells Creek; placement of fill from art upslope slope stabilization area in the bottom of Ells Creek Canyon to create adequate portal bench areas and improve the existing access road; and upgrading of the existing Ells Creek Canyon • road as a haul road. On completion of site preparation, OMI will proceed with cut/fill excavation and installation of two sets (manway and conve}vr/temporary ventilation entries) of steel cirarlar or arch support sections to reach competent ground. Development will continue, with soft- ground excavation of the two main decline entries to the north to intercept the D Coal Seam in the vicinity of Drillhole EG6. Where the main entries intercept the D Coal Seam, the entries will be tamed to the west and expanded to a full five-entryconfiguration, with entries 9 feet high and approximately 18 feet wide. Two ventilation snafu will be sunk from the surface to intercept the maim entries at a depth of approximately200 feet. The ventilation snafu will intercept the mains where theytum to the west. In the five-entry configuration, entry spacing will be reduced co approximately 70-foot centers with cross-arts un 8G to 3vl?--foot Centers, dependeet on gmuad a~rtditioas. ,4r the porrx u#rere tfte main entries tam to the west, entries will continue to the north in the coal seam to create a underground sump for collection and temporary retention for sediment control of mine water inflows. Material excavated from the declines and ventilation snafu will be utilized as fill material for the Elk Creek portal bench and access road if compatible with design compaction specificatioru. Quantities of non-marketable coolly material and any saturated material excavated during mine development are expected to be tttinimal and will be transported to the surface, hauled, and placed in the existing West Valley Fill disposal area. Any saturated materials will be handled and placed to facilitate effective drainage and consolidation. Marketable coal excavated during development wi]] be trartsponed to the surface and hauled by truck to the coal storage stockpile until the conveyor connecting the Elk Creek Mine to Coal Stacking Tube No. 1 is completed. . From the point where the mains nun to the west, mine development wi!! convnue using continctous room and pillar mtnmg methods. Within the limiu of OMI's privatel}~held coal reserves, development can be extended up to approximately 10,000 feet to the west. OMI will ako initiate development of longwall panels 1, 2, and 3, to establish an effective ventilation bleeder system prior to mining. These panek will extend up to 3,500 feet north from the main entries. Since all PR04 2.05-6 Revised August 2000