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Mr. Jack Henris July 13, 2016 Page 10 m:\min\tc1\_teller\m-1980-244 cc-v\am-11\m-80-244-am-11maincommentr12016-07-13.docx for the WH-3 geology. The reference to Figure 6-28 is incorrect as that is for WH-2. Please provide the following: a. Assurance that the appropriate FOS at the edge of the Co Rd Right-of-Way is achievable (reference DRMS Table 1 above), b. Show Teller Co Rd 82 on Figures 6-1, 6-29 and 6-30. 38. Appendix 5 Table 6-2. Only four of the 10 cross sections analyzed have an acceptable FOS for global stability. Please discuss how the mine intends to achieve stable highwalls, keeping in mind FOS standards listed in DRMS Table 1 are required for at least sections GH-4, WH-1 (both with respect to CR 82) and WH-3 (respect to ECOSA). 39. Appendix 5 Figure 6-1. It appears the NW corner of the North Cresson (Globe Hill) mine intersects Poverty Gulch which appears to be confirmed based on discussions in Volume IV, Appendix 10 (pp. 8 – 11, North Cresson and Poverty Gulch Storm Water Management). This raises two concerns: a. Although flow is infrequent in Poverty Gulch, the proximity (if the flow is not actually intercepted) suggests the rock mass may not be accurately described as completely “drained” as stated in paragraph 6.2.2, Hydrology (p. 6-3). Please analyze a cross section roughly perpendicular to Section GH-4 through the NW corner of the Globe Hill pit, assuming saturated conditions. b. The Division will likely consider the stormwater diversion (a.k.a. “bypass”) a critical structure, thereby necessitating an appropriate FOS from DRMS Table 1. Please consider the FOS requirements when evaluating the stability in this area. CC&V’s response to Comment No. 56 may have impacts to this comment. 40. Appendix 6, Paragraph 2.0, Overburden Storage Area Stability Evaluation. The stated factor of Safety goals are 1.3 and 1.15 for static and pseudo‐static conditions, respectively. a. Given the proximity of the ECOSA to both Grassy Creek and Teller Co Rd 81 SW of the Grassy Creek crossing, the Division considers the ECOSA a critical structure and the higher FOS (second row of DRMS Table 1) applies. b. These FOS values are based on DRMS Table 1 strength measurements resulting from multiple tests. However, it appears from the narrative for overburden and colluvium that these values may be based on assumptions (Overburden: “it is NewFields’ opinion that the referenced strength is reasonable for the material”, p. 4 in the text) and empirical relationships (Colluvium: “friction angle (φ) of 29 degrees were developed from an empirical relationship between shear strength, liquid limit and clay fraction of the material”, p. 4 in the text) and not on laboratory tests. Please provide strength test results to justify the use of lower FOS or commit to meeting the Division’s higher FOS for assumed, etc. strength parameters. c. Potential for saturated colluvium. Studies have shown an often overlooked weakness in overburden stockpile stability is the interface between the overburden and the underlying native material. Furthermore, the recent fresh water pipeline