2009-03-02_REVISION - C1980005 - Laserfiche WebLink

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Phase 77 Bond Release Application SL-3 Response to Adequacy Comments Page 3 herbaceous covet, in addition to total covet, in future Phase II or Phase III bond release applications. Response: Total vegetation cover has commonly been used for determining sample adequacy for reclamation success at operations in the western U.S. It has been an approved measure at the Seneca II Mine for a number of years and was most recently affirmed in the approval of Appendix 13-13 to Tab 13 in the Seneca II Mine permit. Since BRB-2 and BRB-3 Phase II bond release studies were carried out in consideration of the currently approved permit and previous successful submittals where sample adequacy was determined using total vegetation cover, SCC believes that the BRB-2 and BRB-3 bond release application should be approved as presented. SCC will commit to revising the approved permit to use the concept of herbaceous cover in determining sample adequacy for future Phase II or Phase III bond release applications. Specifically, all hit herbaceous cover will be proposed for sample adequacy and7statisrical testing in future bond release submittals: Sample adequacy will-be determined for only all hit herbaceous cover and not include an additional adequacy determination for "total cover" (SCC assumes CDRMS meant "total vegetation cover"). In addition, the revision submittal will include a change in the cover success standard based on all hit herbaceous cover. Seneca II-W currently has an approved similar approach. SCC understands that a formal revision must be submitted to CDRMS on this approach and the above is provided for informational purposes only at this time. 3. The Division noted that in t-test demonstrations of succes for BRB 4, the ample standard deviation for total vegetation cover was used, rather than the sample standard deviation for herbaceous cover. Because the sample mean for herbaceous cover is used in the t-test to demonstrate cover success, it is appropriate that the sample standard deviation for herbaceous cover, rather than total vegetation cover, be used as well. Please address this concern, and unless appropriate justification is provided, please commit to timely revision of the approved permit to specify that herbaceous cover sample standard deviation will be used in hypothesis testing for future Phase II or Phase III bond release applications. Response: BRB-4 has been removed from consideration of Phase II bond release in the SL-3 application package. 4. On page 75 of the SL 3 application, SCC addresses permanent impoundments. Under the Permanent Impoundment Documentation heading, information regarding approval of the existing sedimentation ponds as permanent impoundments was provider, but no such information was provided regarding approval of existing stock ponds as permanent impoundments. Please provide information regarding approval of existing stock ponds as permanent impoundments, consistent with the information provided regarding sediment ponds approved as permanent. Response: The forms and approval letter were submitted to the Division on November 17, 2008 as part of TR-46. The approval documentation (dated January 13, 2009) is located in Appendix 13-9, Stock Pond Design - Seneca II Permanent Stock Pond Evaluation. Attached is a copy of the letter from the Division of Water Resources listing the approved stock ponds. 5. We note that in Appendix 73-9 `Permanent Stock Pond Evaluation" of the approved permit, SCC states that 13vater sampling conducted during the bond release period will be used to confirm the assumption that water quality will be suitable for the intended use]" Please take note that water quality suitability demonstrations (for livestock/wildlife use) similar to those provided for permanent sedimentation pond impoundments, will be required for Phase Ill bond release, for each permanent stock pond. We recommend that samples be obtained, analyzed, and suitability demonstrations be submitted for Division review and