_REVISION - M1980244 (31) - Laserfiche WebLink

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_..;~ . Response: uacd r ~: 12 tew•information presented in the Amendment No, 8 application is based on records from the Office s., State Engineer. CC&V has no other information indicating additonal wells or water rights within -i~iae radius of the proposed Amendment No. 8 permit area. Further, CC&V did not attempt to ~riine how many of the wells still exist or whether the associated water rights are currently actively 3ipce there arc no anticipated effects from the Amendment No. 8 activities on those wclls.- D. Under,dhe YLF, r%ti !Water Ealance, the operator slates, 'AS a result ojthe increase in ore depth and the sglurioa from areas afPhase IYwhich will report to the existing Phase 1 and II PSSAs, the capacity of the.;ezlsting PSSAs were evaluated. The resuks indicated once Phase IYis constructed and operational, the: calculated volume necessary for the PSSA for Phase I and II is greater than the available capaciy given the freeboard requirements. This will necessitate using the Phase 1, IJ and Ill external pond far solafiun Storage. ° .: 1. •!s the Phase I, ]I, and III external pond located below the ARD building the same as the one t submitted under TR-33? Are there plans to build additional ponds, other than the ones indicated on thejacllittes Map? Ifyes, please provide the specific design and locarlons for these ponds. Please submit a detailed plan and stability evaluation for the Phase IV External ,Pond, which is also referenced in Section 6.4.3(E). Response:.:Tfie Phase I, II, and III External Pond submitted as part of TR-33 is the same pond shown to be locate¢,below the existing ADR building in Amendment No. 8. The only external solution ponds planned are the Phase I, II, and III External Pond and the Phase IV External Pond. The Phase TV External Pond is presented in Section 4.6.3.2 begirming on page 34 of Appendix 7 in Volume V of the application. Design details are provided in this section and are the same as those for the Phase T, lI, and TIT ~Extemal Pond. Drawing 24 shows the design details for the Phase IV External Pond. This drawing is contained in Volume V of the application. Note from the drawing that the Phase IV External Pond is ah excavated pond and therefore no geotechnical stability analysis was necessary for this pond. ~':. E. As indicated by the operator and at calculated by the Division, without the external pond forPhase I, II, and III; the water balance will exceed the design capacity. The operational WAD CNfor the operation rs ISO PPM IYAD CN. however, the operator has agreed to keep the WAD CN in the external ponds at maximum 40 PPM WAD CN. Please provide a detailed water balance showing how ehe operator is going to maintain and not exceed the BO% operational capacity without exceeding the 40 PPM WAD CN to the external pond. The Division understands the time needed to kill the CN. Ilow is CC&Ygoing to accomplish this task? Please also note that the BO% operational capacity for the YLF can not be exceeded at any given time. If ii does occur, CCdrYhas to nat~ the Division within Z4 hours ofsuch occurrence. ~: x, ail' Respagse:~• Aseries of tests were performed on actual CC&V process solutions to determine parameters used in the design criteria for the WAD CN treaknent system. The tests indicated that a molar ratio of 1.0 H=Oz to 1.Q #1/AD t.AT would reduce a 150 ppm WAD CN solution to approximately 12 ppm WAD CN in less than ~1 hours on the slower reacting cold solutions (S°C). The time would be substantially reduced by depressing WAD CN oonoentrationa from 150 ppm to 40 ppm. The results of these tests indicate that the planned system designed will be able to meet the WAD CN parameters established for the process solutions stored within the external pond within a very short time period. The planned cyanide treatment system will consist of hydrogen peroxide tanks and dispensers at the external storage ponds capable~of treating up to 1,000 gpm of process solution. Based on these tests results, the WAD cyanide treatment system combined with the planned chain link fence and appropriate hazing devices are adequate to protect wildlife. ~~-~~