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7) The operator's response to item no. 13 indicates the Times Mine bulkhead is already <br /> impounding some water. Please provide demonstration the bulkhead is designed to impound <br /> water for the full height of the bulkhead, with completely flooded workings (Times Mine cross- <br /> cut filled with water). This demonstration must include certification by a professional engineer. <br /> Alternatively,the operator can commit to maintaining water levels in the mine workings below <br /> the collar elevation of the 50 foot winze (said to be 8,360 feet). In either case, please describe the <br /> monitoring system that will be utilized to monitor bulkhead pressure. <br /> CMC Response: Deer & Ault Consultants, Inc., of Longmont, Colorado, were retained by CMC <br /> to provide an evaluation of the Times Mine Bulkhead, and their Technical Memorandum <br /> addresses all of the outstanding issues related to the Times Mine Bulkhead. Their Evaluation of <br /> the Times Mine Bulkhead by Christoph Goss, PhD, P.E. dated May 15, 2019 has been attached to <br /> this Response Letter to the DRMS as part of this Amendment to the Gold Hill Mill Limited Impact <br /> Permit. <br /> 8) The operator's response to item no. 12 states that water levels will be monitored by periodic <br /> manual measurements in the Wynona Mine shaft well casing. Please state the frequency that <br /> water levels will be monitored during operations. Additionally, please commit to maintaining the <br /> monitoring records on site to be made available for Division review during inspection. <br /> CMC Response: The water levels in the Wynona Mine will be monitored on a weekly basis when <br /> the Gold Hill Mill begins processing ore.This will help CMC determine the frequency and duration <br /> of pumping operations from Left Hand Creek to replenish the water being consumed in the Gold <br /> Hill Mill. Once the milling operation determines the rate of water consumption from mineral <br /> processing,the frequency of monitoring the water levels in the Wynona Mine may decrease. CMC <br /> will maintain the monitoring records on site for review during inspections by the DBMS. <br /> 9) The operator has indicated the Wynona Mine workings are currently flooded to some extent. <br /> Therefore, please commit to measuring water levels in these workings on a quarterly basis for <br /> five quarters, and submitting this data to the Division a minimum of 60 days prior to <br /> commencing with operations. This information will help demonstrate whether the proposed <br /> 7 <br />