2011-02-15_REVISION - C1980004 (2)

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Corey Heaps McClane Canyon Mining, LLC February 15, 2011 Page 21 PIease see Items 12 and 89 above and provide a plan for one new alluvial groundwater monitoring well to be located immediately down gradient of the proposed refuse pile location. 108. In the mass balance calculation presented at the bottom of page 3 in Appendix N it appears that the gob leachate was inadvertently left out of the calculation. Based on the data presented the resulting combined flow would be 100.69 gpm with an EC of 1875 umhos /cm as opposed to an EC of 1854 as stated on page 3. Please check this calculation and correct the error if appropriate. 109. On page 11 of Appendix N, "Probable Hydrologic Consequences ", it is stated in the first paragraph that there are two possible sources of irrigation water that are located between SW -I and SW -8 which may alter water sampling results. If this is the case, how does MCM propose to show that mining has not had any effect on East Salt Creek? 110. There appears to be a discrepancy in the 2008 and 2009 metals data presented in Table N -8 on page 12 of Appendix N. The values listed do not appear to coincide with the data presented in the 2008 and 2009 Annual Hydrology Reports. Please clarify this and provide an explanation of how the "Average" values listed in Table N -8 were calculated. Rule 2.05.6 (6) Subsidence SurvqL Monitoring, and Control Plan 111. Subsidence has the potential, especially in areas of thin overburden, steep slopes, and cliff outcrops to cause damage to cultural resources, including rock art, rock shelters, and pictographs. From review of the project location map in Appendix J of the revision application, it is not clear that areas planned to be subsided were included in the cultural resources survey. Please identify cliff faces and areas of potential rock art within the area to be subsided (affected area), show them on a map, and submit the appropriate resource surveys for those areas so that the Division can forward this information to the SHPO. 112. Please expand the brief text discussion on page 2.05 -71 under Rule 2.05.6(6)(b)(i)(B) regarding the magnitude of vertical subsidence as it relates to the depth of overburden. Reference to a map for those areas of high risk of surface cracking would be helpful. 113. The Division believes that in areas of shallow overburden (c500 feet) and steep slopes, the potential exists for surface cracks to develop that may be a hazard to recreational use and grazing. Please consider a plan for periodic monitoring and. mitigation (if warranted), for these areas. 114. Regarding the potential for surface cracking, permit text narrative on page 2.05 -71 uses the term "retreat line" as a reference for identifying surface cracking develop "parallel" to this line. Please modify permit text narrative, explain the orientation of the retreat line, and /or be more specific on the expected orientation of surface cracks. 115. On page 2.05 -71, permit text narrative states "cracks could be a few inches wide and long enough to go across the entire roadway." How was this conclusion reached? What study or