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been under a CDPHE discharge permit. Water quality of the current and past discharge is also <br /> enclosed in Appendix B. The Leadville Limestone buffers the water so that the pH is in a normal <br /> range throughout the mine and the water quality overall is good. <br /> It is assumed that the new drill holes will encounter water but this is not definitely known. <br /> Precautionary measures will be taken to plug every hole as soon as the drilling stops if any water <br /> leaves the hole. The existing water leaving the mine will not be affected. <br /> 6—The measures to be taken to ensure that the existing water in the mine ditch will be <br /> unaffected are as follows: <br /> a) All drill holes will be plugged as soon as they are completed or if a significant amount of <br /> water is encountered in the drilling process. In this case the full planned hole depth may <br /> not be drilled, but in this way,there will be no change to the quantity and quality of water <br /> in the mine ditch. Before any hole is plugged, if water is present, it will be sampled for <br /> complete analysis. This analysis will be presented to the Division in the Reclamation <br /> Report for the NOI Project. <br /> b) Around each drill location(5 total), a ring of 5 rows of erosion control waddles will be <br /> placed so that any water from the drill hole will have to pass through the waddles to get <br /> back to the mine ditch. <br /> c) The water leaving the waddles will be inspected every 30-60 minutes during the drilling <br /> operation. If any water leaving the waddles shows any sign of sediment, additional <br /> waddles will be placed. If for any reason the sediment level in the water leaving the drill <br /> site cannot be made to be clear,the operation will shut down immediately until a solution <br /> can be found. The commitment has been made to not affect the existing water in the mine <br /> ditch and this commitment will be kept. <br /> d) In addition, Imhoff cone tests will be conducted of the water leaving the portal for 4 days <br /> before the project has started and every day (once per day) as drilling is conducted. If the <br /> Imhoff cone tests show any appreciable change to the water leaving the mine, the drilling <br /> operation will be stopped and any active hole will be plugged. After the underground <br /> activity ends,the sampling will continue for a minimum of 7 more days to demonstrate <br /> that the water has not been affected. All of these results will be presented in the <br /> Reclamation Report of the NOI Project delivered to the Division. <br /> e) If at any time during the project,the operator feels that the existing water in the mine has <br /> been affected, the DRMS and the CDPHE will be notified immediately and any <br /> corrective actions will be taken immediately. <br /> f) Use only a biodegradable polymer additives in the drilling process, if needed.No other <br /> chemicals will be used. <br /> Employing the above measures will ensure that the existing water is unaffected and that a <br /> discharge permit will not be needed for the NOI, based on previous experience at the Revenue <br /> Mine. <br /> 7—The holes will be grouted immediately after completion or at any time during the drill <br /> process if significant new water is emanating from the drill hole. <br />