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that block. The number of entries remain the same, but their final location may have changed within the block to <br />provide operational flexibility to address site-specific mining or geological conditions. The same concept applies to <br />the west end of the panel where the mains and beginning of the 12 -Right Panel is shown. The entries may have <br />shifted within the panel limits, so long as they are within the boundary of the 12 -Right Longwall Panel. <br />Northwest Mains Reorientation (MR00-167) <br />TC reoriented the Northwest Mains to the East in order to improve pillar stability. During initial development, the <br />main entries were driven parallel to the coal cleat, however, this did not prove to be a stable configuration and <br />resulted in excessive pillar sloughage. Reorientation of the mains to the east results in an entry alignment at an <br />angle to the cleat, which increases pillar stability. Reorientation of the mains also resulted in recovery of additional <br />federal coal (Lease CO -54608), with a corresponding decrease in recovery of the adjacent fee coal, adding <br />approximately 6 acres of federal coal to the mine area. Realignment of the mains is shown on Map 23, Mine Plan. <br />Also associated with this revision is widening of the initial 1,000 feet of the 11 -Right Gate -road. The number of <br />entries remain the same; only the pillar width of the southern entry is increased, as shown on Map 23. <br />Northwest Mains Reorientation (MR03-182) <br />In late 2002, TC completed several exploration projects using a combination of surface seismic lines and drillholes. <br />The data from these projects allowed TC to better define the fault system to the east, the steep grades to the north <br />and west, and the fault crossing between the Northern and Western Mining Districts. As a result, TC reoriented the <br />Northwest Mains towards the west and north to maximize the mineable coal reserves to the north. The Northwest <br />Mains were turned in a southwesterly direction at a location just inby the 17 -Right Gate -road. The Northwest Mains <br />continued in this direction towards the fault that currently runs between the Northern NMD and WMD. <br />Development mining was then used to confirm the extent and configuration of the faulted zone. After exploring the <br />extent of the fault, the Northwest Mains were again turned in the northwest direction to access the northern <br />reserves. This orientation of the Northwest Mains maintains entry alignment at an angle to the cleat for stability. <br />The location and orientation of the panels and the mains are shown on Map 23, which also shows increased panel <br />lengths for Panel 19 -Right and subsequent panels. <br />The 16 -Right Panel was shortened by approximately 500 feet due to adverse roof conditions encountered during the <br />development of the gate -roads. TC maximized coal recovery in this panel to the extent possible within the <br />constraints of the roof conditions. Projections for the panel are shown on Map 23. <br />NMD (Panels 12 -Right through 16 -Right, PR99-05; 17 -Right through 23 -Right, PR03-06; 21 -Right through <br />24 -Right, and WMD (Panel 13 -Left through 17 -Left (preliminary development) - PR06-07, TR07-63) <br />The NMD will increase the affected area within the Permit Area, i.e. areas overlying longwall panels and adjacent <br />areas within the projected subsidence limits, by approximately 4,170 acres. The area to be mined in the NMD is <br />shown on Map 23, Mine Plan, and identified by color -coding. The mining layout will include longwall panel <br />lengths up to approximately 15,000 feet, a longwall panel width of 1,000 feet, and gate -road, and mine <br />development work as described in the referenced Permit Revisions. The dimension of pillars in these development <br />areas may vary based upon mining conditions. Sumps and ventilation doglegs will be added as needed. Locations <br />for these minor operational features are not shown on Map 23, due to the need for some operational flexibility in <br />placement. <br />During the remaining NMD development and mining, undermining and related subsidence of the Fish Creek AVF, <br />Fish Creek, the Union Pacific Railroad, several powerlines, two reservoirs owned by the Ashleys, and several stock <br />ponds will occur. A more detailed discussion of undermining these structures is presented under the subsidence <br />discussion. <br />WESTERN MINING DISTRICT (PR06-07, PR09-08, PR12-09, TR07-63, TR08-64 TR09-68, TR09-71, <br />TR13-82) <br />Initial development (Phase 1) in the WMD will increase the affected area within the Permit Area, i.e. area overlying <br />longwall panels and adjacent areas within the projected subsidence limits, by approximately 200 acres; Phase lI <br />TR13-82 2.05-17 02/28/13 <br />