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planned) orientation was optimal for stability of the rooms with respect to the horizontal stress <br />field. As stated in 4.1 - Mains Orientation, "the rule of thumb is that the mains should be oriented <br />near parallel to maximum horizontal stress to minimize roof stability problems." The orientation <br />of the mains evaluated by Maleki was N 100° E, which was deemed to be favorable because it lay <br />within 20 degrees of the maximum stress orientation (N 90° E). However, the orientation of the <br />mains illustrated on revised Maps 14-B and 27 appears to be N 55° E, which is skewed 35 degrees <br />from the maximum stress orientation. <br />The bearing of the West Mains corridor has been rotated 45 degrees from the layout evaluated <br />in 2004. Please re-evaluate the stability of near-seam strata using the corridor layout now <br />proposed with TR-65. <br />18. An evaluation of pillar stability, using MULSIMTI, is presented in Section 4.2. Factors of safety <br />ranging from 1.64 to 2.5 were determined for the layout utilized. However, as discussed in the <br />preceding item, the orientation for the mains now proposed with TR-65 differs by 45 degrees from <br />what was evaluated for the Maleki report. <br />Please re-evaluate the anticipated pillar stress levels and factor of safety expected, given the <br />proposed change in orientation of the corridor beneath Terror Creek, and verify that the <br />required factor of safety will continue to be achieved. <br />19. Maleki Section 5.0 - Overburden Stability <br />Please provide a statement addressing potential (if any) impact to the anticipated stability of the <br />overburden that may be expected due to the proposed change in orientation of the West Mains. <br />General Comments - Maps <br />20. Map 07 - Geology <br />A. Was not submitted with the application; should be revised to show proposed TR-65 <br />changes. <br />21. Map 09 - Hydrological Monitoring Location <br />B. The Legend does not provide a description of the solid brown area. <br />22. Map 27 - Subsidence <br />A. The heavy red and purple lines that represent the burn limits for the B and D Seams <br />are not identified in the legend. <br />B. Subsidence Monuments 37-A thru 37-D are "proposed" with TR-65, but the symbol <br />used does not reflect that status. <br />C. The legend does not have a symbol for the electric transmission line. <br />D. The legend does not have a symbol for the transmission towers. <br />E. The Outcrop -D line is missing for the eastern portion of the map. <br />F. While there are UTMgrid crosshairs on the map, there is no North arrow. <br />4