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Based on this material balance, it can be assumed that no sand need be hauled from the <br /> active mining area. The applicant requests that the Division revise the bond calculation <br /> with this assumption. <br /> Exhibit S—Permanent Man-Made Structures (Rule 6.4.19) <br /> 3. The revised Map C-1 shows the all surrounding fence owners. Many of these fence <br /> locations are not known exactly but are assumed to be between property owners based on <br /> observations made during site visits. The applicant is pursuing structure agreements with <br /> all of these landowners with regards to these fences out of an abundance of caution. <br /> 4. Mail certifications for all neighboring structure owners have been attached. <br /> Geotechnical Stability Exhibit <br /> 5. Map C-2 has been revised to show the correct setbacks. Mining will stay 30 feet from <br /> gaslines and 10 feet from powerpoles. These setbacks are based on the structure <br /> agreements from the original MLRB permit application. <br /> 6. Attached to this adequacy is the results of a GALENA software slope stability analysis. <br /> This analysis shows the failure slope for a vertical highwall that has a Factor of Safety of <br /> 1.5, which is the minimum required by the Division when adjacent to critical structures <br /> such as utilities. The failure circle for this Factor of Safety is 11 feet away from the <br /> highwall crest. This is less than the 90-foot offset to a gas line,the 25-foot for power <br /> poles, and the 50-foot for all other structures. See Figure 1. <br /> Any failure slope with a FOS of 1.5 or lower will be further away from these structures <br /> than the required setback. This is shown in the GALENA data results as well. <br /> Additional Geotechnical Stability Analysis <br /> A more detailed geotechnical stability analysis using GALENA was also conducted for the <br /> mining slope nearest to an existing structure not owned by the applicant. This is the Pioneer <br /> Natural Resources, Inc. gas pipeline that runs along the north side of the current pit in Area 1. <br /> The current slope is 1.51-1:I V with a maximum depth of 30 feet. Using the same material as the <br /> Vertical Highwall Analysis (phi =45°; unit weight= 110 pcf)the minimum FOS of this slope is <br /> 1.5. This is sufficient of factor of safety for slopes near critical infrastructure. If structure <br /> agreements cannot be completed prior to the decision date,this analysis should suffice under <br /> Rule 6.14.9. <br /> Robinson Pit No. 1 2 4nk I cHn Ai anJ �s nri,+U ti,I'I, <br />