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Mr. Jack Henris <br />July 13, 2016 <br />Page 5 <br />m:\min\tc1\_teller\m-1980-244 cc-v\am-11\m-80-244-am-11maincommentr12016-07-13.docx <br />complete, please provide it to the Division. If not, please indicate when the evaluation is <br />expected to be completed and commit to providing the evaluation to the Division. <br />15. Page 4-6, Section4.6.1 Surface Water. Of the named tributaries in this first paragraph, labels <br />for Theresa Gulch and Bateman Creek could not found on either Figure G-1 or G-2. Please <br />label these two tributaries on both Figures G-1 and G-2. <br />16. Page 5-10, Section 5.3.4 Mine Area Stability. The last sentence indicates there have been <br />no “observable slope failures other than occasional bench raveling.” The Division is aware <br />of the movement/slope failure in the south end of the WHEX that caused the mine to relocate <br />the previously planned adit in the WHEX. Please explain why this is not considered an <br />observable slope failure. <br />17. Page 5-15, Section 5.4.3 Underground Hauling and Mucking. The last sentence indicates <br />development rock may be temporarily store on the surface prior to being hauled to an <br />existing overburden storage area. Please indicate where the temporary storage will be, how <br />long is temporary and how the potential for acid rock drainage will be controlled in these <br />temporary storage location(s). <br />18. Page 5-15, Section 5.4.4 Schedule. The second paragraph references a planned raise bore <br />to allow sufficient ventilation for stope mining. Please indicate where the raise bore is <br />expected to daylight on a map (Note: This may be the same issues discussed in Comments <br />8 and 9 above for Drawings C-5a and C-5b). <br />19. Pages 5-17 to 5-18, Section 5.6.2 East Cresson Overburden Storage Area. The paragraph <br />under the “General” subsection indicatesMLE2/AM10extended the ECOSA to <br />approximately 274 acres. The second paragraph under the “Construction” subsection (p. 5- <br />18) suggests the ECOSA footprint nearly doubles in size to 500 acres. Please explain the <br />apparent discrepancy in the ECOSA footprint. <br />20. Page 7-1, Section 7.2.1 Stability Analysis. The factors of safety (FOS) for the SGVLF are <br />stated to be 1.3/1.5 for operation and reclaimed static conditions, respectively; and 1.0/1.1 <br />for the pseudo-static conditions during operations and reclamation, respectively. The <br />Division has adopted new FOS standards for slope stability as shown in DRMS Table 1 (top <br />of p. 6). The stated FOS for static conditions meets the Division’s new criteria (right column <br />applies in most cases as numerous tests have been performed on the VLF material to <br />establish strength parameters). It should be noted the Division considers state highways and <br />county roads to be critical structures. Neither the operational, nor reclamation FOS for <br />pseudo-static conditions satisfies the new criteria. However, as the SGVLF was approved <br />with MLE2/AM-10, prior to the Division’s adoption of these criteria, we will not require a <br />change to the design slope. The Division is also aware of an annual geotechnical <br />assessment/evaluation of mine slopes performed by outside consultants. The Division <br />requests a commitment from CC&V to provide a copy of the report generated from this <br />annual slope stability assessment. <br />