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GoodMiller #2 Second Stability Review <br />Page 2 of 2 <br />March 11, 2015 <br />1.6H:1V Mined Slope <br />The Applicant's cross section with power pole loading added was duplicated for verification. <br />The safety factor produced by Galena is lower (1.41) than the safety factor produced by the <br />Applicant's calculation (1.65); however the factor of safety is greater than the required safety <br />factor of 1.3. Therefore, the accuracy of the Applicant's analysis is confirmed. A copy of the <br />Galena model is attached. <br />3H:1V Reclamation Slope <br />The Applicant's cross section with power pole loading added was duplicated for verification. <br />The safety factor produced by Galena (2.24) is greater than the required safety factor of 1.3. <br />Therefore, the proposed slope and configuration is confirmed. A copy of the Galena model is <br />attached. <br />Conclusion <br />The Division agrees with the proposed setback and mining and reclamation slope angles for the <br />GoodMiller #2 Pit. The excavation along the east side of the pit adjacent to the overhead <br />power lines and County Road 115 must never exceed a slope of 1.6H:1V, groundwater must not <br />be intercepted at the proposed maximum mining depth of 40 feet and the site soil profile <br />consists of GC (clayey gravels, poorly graded gravel- sand - clay). If groundwater is intercepted <br />shallower than expected and /or the soils differ from the expected profile, the Applicant must <br />contact the Division immediately and reevaluate the stability analysis based on the corrected <br />information. The Applicant must understand that any transgression of the sloping criteria will <br />be considered a serious violation of the permit if it is approved and issued. <br />If you have any questions, please contact me at (303) 866 -3567 Ext. 8124. <br />Sincerely, <br />Peter S. Hays <br />Environmental Protection Specialist <br />Cc: Tom Kaldenbach, Division of Reclamation, Mining & Safety <br />