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DEG.~2'96~THU) 1025 WRIGHT WATER TEL 303 480 1020 P. 003 Memorandum to CDMG December 12, 1996 Page 2 drilling in the Box Canyon PR azea, there has been a lack of water and methane encountered in or above the Oliver No. 2 mining horizon. Lateral Constraint -This factor refers to whether the immediate overburden above the coal seam daylights, especially down~ip. The B-seam, where MCC mining will occur, is . laterally constrained throughout the Oliver No. 2 Mine area and the Box Canyon PR area. The E/DO-seam does not daylight in the Box Canyon PR area. At the Oliver No. 2 Mine, the E/DO-seam does daylight near the North Fork Gunnison River (North Fork). However, projecting a very conservative angle of draw from the MCC Box Canyon panels, only the northern-most panel will have a very limited area of influence on the Oliver No. 2 Mine. Precedence -There is no evidence that supports the occurrence of block movement at the West Elk Mine. Furthermore, interviews with state geologists and literature reviews showed no precedent for block movement at these dip angles. The above factors lead WWE, along with Messrs. Dunrud and Rold, to conclude that block movement due to mining the B-seam in the Box Canyon PR area is extremely unlikely to impossible. Dr. Pendleton pointed out that ARCO had previously performed a stability analysis relative to the F-seam at West Elk Mine. The dip angle was approximately 5° and the F-seam was underlain by a "nasty" floor clay. Even with these adverse factors, the analysis concluded that the overburden was stable. Dr. Pendleton further remazked that this concern was originally brought up based on the regional dip angle of approximately 6°. With the existing dip angles, he agrees that block movement is extremely unlikely. However, he suggested that MCC might want to install a single filament extensometer in one of their open drill holes to demonstrate that no movement is occurring. MCC appreciated the suggestion and is investigating the feasibility. FRACTURE-CONTROLLED DRAINAGES Mr. Rold of W WE presented an overview of several studies that demonstrated that even with drainages that are fracture controlled, the different stratigtaphic units typically have different fracture orientations. References included the USGS research in the Green River Formation in the Piceance Creek basin and the DOE "MX" oriented coreholes in the Mesaverde Formation near Battlement Mesa. Mr. Duttrud pointed out that the lack of connectivity between surface fractures and subsidence fractures is further enhanced by two key factors. First, using the most conservative estimates, the fracture zone will not extend more than 240 Feet above the mine workings. Dr. Pendleton noted that based on his experience he does not believe fractures extend beyond 100 feet above the B-seam. Even using the higher estimate, there is sufficient overburden so that there will be a continuous deformation zone several hundred feet thick