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2.0 MINING METHOD <br />The longwall mining method will be utilized in the South of Divide and Dry Fork mining areas. The <br />planned panel design is similar to the B Seam West Elk Mine longwall panels where subsidence <br />measurements were used to obtain the baseline data that will be used in this report. A range of 8 to <br />14 feet of coal will be extracted from the E Seam (Figure 1). The extraction thicknesses are <br />projected based on exploration hole data; actual thicknesses may vary depending on mining <br />conditions encountered <br />Longwall panels E1. through E8 are projected to be 1,080 feet wide and range from about 10,000 to <br />15,000 feet long. Panel E9 is projected to be 1,080 feet wide and 5,750 feet long. The panels will be <br />mined by the retreat longwall method. Panels E1 through E8 will be mined from east to west. Panel <br />E9 is planned to be mined from south to north. <br />The trend of panels E1 through E8 is approximately N80°W. Panel E9 trends roughly N101E. The <br />overburden depth above the panels E1 to E4 ranges from roughly 375 to 1,425 feet, whereas, the <br />overburden depth for panels E5 to E8 ranges from 500 to 1,400 feet. The overburden above panel <br />9 ranges in thickness from 500 to 600 feet. <br />All longwall panels are planned to be separated by two or three rows of chain pillars. The row <br />nearest to the headgate side of the panels is projected to be a rigid pillar design-on centers 125 <br />feet wide by 200 feet long. The row on the tailgate side of the panel will be of a yield pillar design- <br />on centers 75 feet wide by 200 feet long. A protective barrier system, 700 feet wide, is currently <br />projected to separate the longwall panels E1 to E4 and E5 to E8. These mine plans and pillar <br />designs may change as mining experience, geological-geotechnical conditions, and/or mine <br />operational procedures dictate. <br />• <br />Tetra Tech - 0907171P