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Varra - Coulson - Third Stability Analysis <br />Page 2 of 2 <br />April 18, 2014 <br />The Applicant's cross section was duplicated for verification to represent the worst case <br />scenario for this slope configuration. The safety factor produced by Galena is significantly <br />lower (1.23) than the safety factor produced by the Applicant's model (1.416). Therefore, <br />this slope configuration is unacceptable for the Critical Slope Areas of the proposed site. A <br />copy of the Galena model is attached. Since the factor of safety was less than 1.3, the <br />Division will require the Applicant to obtain structure agreements for all property, <br />including easement holders, and structure owners within two hundred feet of the affected <br />land or reconfigure the slope configuration to produce a factor of safety greater than 1.3. <br />The Division recommends a single slope configuration be proposed by the Applicant. <br />Cross Section No. 3 <br />• Typical "Critical Slope Area" with 3:1 to 1.25:1 Mine Slope with 10' offset, bedrock <br />pit floor material and topsoil stockpile loading <br />The Applicant's cross section was duplicated for verification to represent the worst case <br />scenario for this slope configuration. The safety factor produced by Galena is lower (1.33) <br />than the safety factor produced by the Applicant's model (1.406); however it is above the <br />required safety factor of 1.3. Therefore, the accuracy of the Applicant's analysis is <br />confirmed. However, since a majority of the perimeter boundary of the site will be <br />completed with unconsolidated material in the pit floor, based on Hanes Property borings <br />H -1, H -2, H -3, H -6, H -7, H -8 and H -14 the cross section does not accurately represent the <br />final reclamation perimeter slope configuration at the site. <br />If you have any questions, please contact me at 303 - 866 -3567 Ext. 8124. <br />Sincerel , <br />Peter S. Hays <br />Environmental Protection Specialist <br />Enclosures <br />Cc: Tom Kaldenbach - Division of Reclamation, Mining & Safety <br />Joby Adams - AWES, LLC (by email) <br />