2012-02-03_REVISION - M1978315 (6)

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Red Rock Pit, Permit No. M -1978 -315 112 Permit Conversion Application Response to Adequacy Comments Page 2 • 6.4.19 Exhibit S — Permanent Man -made Structures Where the mining operation will adversely affect the stability of any significant, valuable and permanent man -made structure located within two hundred (200) feet of the affected land, the applicant may either: (c) where such structure is a utility, the Applicant may supply a notarized letter, on utility letterhead, from the owner(s) of the utility that the mining and reclamation activities, as proposed, will have "no negative effect" on their utility. It appears that portions of the power line and telephone line, as shown on the Pre - Mining Plan map, lie within two hundred of the affected land. Please submit letters, satisfying the requirements shown above, for each of these utilities. Response: Letters from Yampa Valley Electric Association (powerline) and CenturyLink (buried phone line) are attached. These letters verify that there will be no impact to the utilities. • 6.5 Geotechnical Stability Exhibit (1) On a site - specific basis, an Applicant shall be required to provide a geotechnical evaluation of all geologic hazards that have the potential to affect any proposed impoundment, slope, embankment, highwall, or waste pile within the affected area. (2) On a site - specific basis, an Applicant shall be required to provide engineering stability analyses for proposed final reclaimed slopes, highwalls, waste piles and embankments. An applicant may also be required to provide engineering analyses for certain slopes configuration as they will occur during operations, including, but not be limited to, embankments. Information for slope stability analyses may include, but would not be limited to, slope angles and configurations, compaction and density, physical characteristics of earthen materials, pore pressure information, slope height, post - placement use of site, and information on structures or facilities that could be adversely affected by slope failure. (3) Where there is potential for off -site impacts due to failure of any geologic structure or constructed earthen facility, which may be caused by mining or reclamation activities, the Applicant shall demonstrate trough appropriate geotechnical and stability analyses that off -site areas will be protected with appropriate factors of safety incorporated into the analysis. The minimum acceptable safety factors will be subject to approval by the Office, on a case -by case basis, depending upon the degree of certainty of soil or rock strength determinations utilized in the stability analysis, depending upon the consequences associated with a potential failure, and depending upon the potential for seismic activity at each site.