2010-06-04_PERMIT FILE - C1982056A (9)

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that block. The number of entries remain the same, but their final location may have changed within the block to provide operational flexibility to address site - specific mining or geological conditions. The same concept applies to the west end of the panel where the mains and beginning of the 12 -Right Panel is shown. The entries may have • shifted within the panel limits, so long as they are within the boundary of the 12 -Right Longwall Panel. Northwest Mains Reorientation (MR00 -167) TCC reoriented the Northwest Mains to the East in order to improve pillar stability. During initial development, the main entries were driven parallel to the coal cleat, however, this did not prove to be a stable configuration and resulted in excessive pillar sloughage. Reorientation of the mains to the east results in an entry alignment at an angle to the cleat, which increases pillar stability. Reorientation of the mains also resulted in recovery of additional federal coal (Lease CO- 54608), with a corresponding decrease in recovery of the adjacent fee coal, adding approximately 6 acres of federal coal to the mine area. Realignment of the mains is shown on Map 23, Mine Plan. Also associated with this revision is widening of the initial 1,000 feet of the 11 -Right Gate -road. The number of entries remain the same; only the pillar width of the southern entry is increased, as shown on Map 23. Northwest Mains Reorientation (MR03 -182) In late 2002, TCC completed several exploration projects using a combination of surface seismic lines and drillholes. The data from these projects allowed TCC to better define the fault system to the east, the steep grades to the north and west, and the fault crossing between the Northern and Western Mining Districts. As a result, TCC reoriented the Northwest Mains towards the west and north to maximize the mineable coal reserves to the north. The Northwest Mains were turned in a southwesterly direction at a location just inby the 17 -Right Gate -road. The Northwest Mains continued in this direction towards the fault that currently runs between the Northern NMD and WMD. Development mining was then used to confirm the extent and configuration of the faulted zone. After exploring the extent of the fault, the Northwest Mains were again turned in the northwest direction to access the northern reserves. This orientation of the Northwest Mains maintains entry alignment at an angle to the cleat for • stability. The location and orientation of the panels and the mains are shown on Map 23, which also shows increased panel lengths for Panel 19 -Right and subsequent panels. The 16 -Right Panel was shortened by approximately 500 feet due to adverse roof conditions encountered during the development of the gateroads. TCC maximized coal recovery in this panel to the extent possible within the constraints of the roof conditions. Projections for the panel are shown on Map 23. NMD (Panels 12 -Right through 16- Right, PR99 -05; 17 -Right through 23- Right, PR03 -06; 21 -Right through 24- Right, and WMD (Panel 13 -Left through 17 -Left (preliminary development) - PR06 -07, TR07 -63) The NMD will increase the affected area within the Permit Area, i.e. areas overlying longwall panels and adjacent areas within the projected subsidence limits, by approximately 4,170 acres. The area to be mined in the NMD is shown on Map 23, Mine Plan, and identified by color- coding. The mining layout will include longwall panel lengths up to approximately 15,000 feet, a longwall panel width of 1,000 feet, and gate -road, and mine development work as described in the referenced Permit Revisions. The dimension of pillars in these development areas may vary based upon mining conditions. Sumps and ventilation doglegs will be added as needed. Locations for these minor operational features are not shown on Map 23, due to the need for some operational flexibility in placement. During the remaining NMD development and mining, undermining and related subsidence of the Fish Creek AVF, Fish Creek, the Union Pacific Railroad, several powerlines, two reservoirs owned by the Ashleys, and several stock ponds will occur. A more detailed discussion of undermining these structures is presented under the subsidence discussion. • WESTERN MINING DISTRICT (PR06 -07, PR09 -08, TR07 -63, TR08 -64 TR09 -68, TR09 -71) Initial development (Phase 1) in the WMD will increase the affected area within the Permit Area, i.e. area overlying longwall panels and adjacent areas within the projected subsidence limits, by approximately 200 acres; Phase II TR09 -71 2.05 -17 11/18/09