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w~: Erk M,~ <br />1. The existing longwall panels at the mine site have been extensively monitored and W WE <br />has evaluated the relevant data. These data provide the basis for Mr. Dunrud's <br />conceptual model, which is described later within this permit text and in Exhibit 60. <br />Please note that Exhibit 60 addresses the Apache Rocks and Box Canyon mining area <br />and Box Canyon lease tract. <br />2. WWE has utilized a computer model to quantify subsidence, and this model has been <br />calibrated using the data collected at the West Elk Mine. The model was developed by <br />Dr. Syd Peng and Dr. Yi Luo at West Virginia University and is refereed to as the <br />"Comprehensive and Integrated Subsidence Prediction Model (CISPM). " <br />3. WWE has thoroughly reviewed the literature regarding subsidence and associated <br />hydrologic consequences. We have checked the findings associated with Mr. Dunrud's <br />conceptual model and the CISPM model with findings from case studies as described in <br />the literature, and we have concluded that the iesults are consistem. <br />4. Finally, subsidence grojections described herein have been cazefully reviewed by <br />Richazd Dunrud for reasonableness. Mr. Dunrud has visited the West Elk Mine area on <br />many occasions and he is quite familiar with all of the key factors pertaining to <br />subsidence as they relate to the Apache Rocks and Box Canyon mining azeas. <br />Consequently, Mr. Dunrud is well qualified to draw conclusions about the nature of <br />subsidence that is likely to occur. <br />.. Subsidence Survey - 2.05.6 (61(bl(iiil(Al & (61(el <br />The following information documents subsidence processes that have been observed from studies <br />above longwall mining panels in the current West Elk Mine permit area. The subsidence data <br />obtained in the current West Elk Mine azea have been used to project subsidence processes, <br />amounts, and effects into the Apache Rocks and Box Canyon mining areas. These data have been <br />used to calibrate the subsidence prediction models described above. <br />In addition to relying on actual subsidence data, WWE has concluded that many of the findings <br />pertaining to subsidence and probable hydrologic consequences from the Apache Rocks permit <br />revision (PR06) apply to the Box Canyon permit revision and mining azea. The basis for this <br />conclusion is as follows: <br />• Comparison of lithologic data from boreholes in the Jumbo Mountain, Apache Rocks <br />and Box Carryon mining areas show consistency in the B-seam overburden materials. <br />While direct correlation of lithologic units, excluding coal beds, is generally difficult, <br />comparison of lithologic logs shows very similar alternating sequences of shales, <br />claystones, and sandstones. In the Box Canyon mining area, a noted exception is the <br />occurrence of the Ohio Creek Member of the Mesaverde Formation and the Wasatch <br />Formation, which comprises the upper reaches of West Flatiron. However, its <br />lithologic chazacter is similaz to the Barren Member of the Mesaverde Formation which <br />• underlies it <br />2.05-100 RevisedJ~m. 1995PR06;!/96RN03; Revised May l9997R89: ReviredJmi 1998 PR08 <br />