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I • Stability Analysis <br />See Buckhorn Geotech's Stability Evaluation of Proposed Coal Waste Pile No. 3, <br />dated March 29, 2007 following this section. Following is an excerpt from the <br />report's stability evaluation results: <br />Factors of safety from critical failure surfaces for each cross-section are <br />summarized in Table 9. Output from these critical stability analyses is presented <br />in Appendix E. The slopes and total height of the gob pile were optimized in <br />order to achieve a minimum factor of safety of 1.50 for both total and effective <br />stress analyses. As indicated in Table 9, four gob geometries and heights result <br />in a factor of safety of at least 1.50: <br />2.5H:1V gob slopes to a maximum gob height of 95 vertical feet <br />• 2.H: 1V gob slopes from 0-50 feet and 3H: 1V from 50 to 105 feet <br />(ultimate height) <br />• 2.5H:1 V gob slopes from 0-50 feet and 3.5H:1 V from 50 to 110 feet <br />(ultimate height) <br />• 3H: 1V gob slopes to a maximum gob height of 115 feet <br />As noted in Table 9 and in Appendix E, the ultimate gob pile height discussed in <br />• this report is measured from the down slope toe of the wastepile to the top of the <br />pile, <br />The Operator commits to having a qualified third party geotechnical firm perform <br />monitoring and testing. Monitoring will consist of observations of the <br />geotechnical aspects of the construction fo determine if any unusual or <br />unexpected conditions are encountered. Testing will include compaction tests <br />and periodic strength tests. Results of the tests and any observed unusual or <br />unexpected conditions will be submitted to the DRMS with the quarterly <br />inspection reports. <br />TR-45 - 11 - 07/07 <br />~PPP~vE~ <br />7~/0 ~ <br />