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~1r. Billy Owens November Z2, 2006 Page 2 Easting 1,436,600 and 1,437,500) the e~asting slide face and corresponding tension cracks look to be at medium depth. Inspection of this area indicates that the cracking occurs at generally deeper depths than encountered in the Task 2 area Where the cracking occurs at deeper depth, most of the material remaining standing is a weaker sandstone with very little competent rock within the zone. We believe that this area can be knocked down and sealed while keeping operators from working under scarp faces by working into the area from the west to the east (using the area described in Task 2 as a starling point) and by reducing the scarp faces as the dozers work east into the higher cover. The sealing work proposed under Task 5 will be done during daylight hours only using experienced dozer hands familiar with the hazards associated with working around highwalls. The work area will be inspected twice per shift while the work is ongoing. Two paths of egress will be maintained at all times, and positive communication will also be maintained. Equipment operators will be informed ofthe presence of any new cracks or signs of instability in the vicinity of their assigned work area and will approach these features in a manner that ensures then safety using the techniques that are commonly employed when working in and around highwalls (i.e. slot dozing techniques). Spotters will be utilized if necessary as conditions warra~. Task 3ladditional information): MSIiA has requested additional detail regazding the proposed buttress construction previously described as Task 3. Three Figures are included for your review. Figures 1 and 2 provide plan and isometric views of the buttress design. Figure 3 details two cross-sections drawn through the proposed bumess. The red colored surface on the plan and isometric views represents the top of the bumess. This is the elevation the dozer work will take place on. The orange colored surface represerns the angle of repose surface on the north facing slope of the material comprising the buttress (approximately a 1.Sh:1 v slope]. PAGE Task 5 and Task 3 are both proposed to be conducted in a manner that prevents equipment operators from working either directly beneath or on top of unstable scarp faces. In both cases, equipment operators will progressively work into construction zones from positions that ensure their safety at all times. For Task 3, the buttress will be advanced from east to west with the dozer working on top of the fill material as it is pushed and built out into the pit north of the exposed H-seam coal. For Task 5, Work will advance into the area from the west and material will be dozed as necessary to maintain a stable work surface beneath the equipment and to ensure that exposures to overhead scarp face instability hazards are eliminated. 03/07 S:\MSHACOMI'1K Otda Mod Raque4 I!2 (f~ks 3 and 5).doc