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for the bulkhead, 7.6 psi (with 17.6 feet of head) during operations, including weekly monitoring <br /> of bulkhead pressure. <br /> CMC Response: CMC commits to maintaining the Times Mine Bulkhead pressure below 7.6 psi <br /> (with 17.6 feet of head) during operations until the DRMS has reviewed and approved the new <br /> bulkhead evaluation based on the results of the proposed pumping test, which may include <br /> different recommendations than those included in the Deere & Ault Consultants evaluation of the <br /> Times Mine Bulkhead submitted on May 17, 2019. CMC commits to conduct weekly monitoring <br /> of the Times Mine Bulkhead pressure during operations. <br /> 4) The operator's response to Item no. 1(f) states the operator is awaiting the results of the Deere <br /> & Ault's mine pool control plan and monitoring plan to determine the frequency of the <br /> inspection of the Times Mine bulkhead. <br /> Please be advised, until the Division has reviewed and approved the new engineer bulkhead <br /> evaluation based on the results of the proposed pumping test, and including different <br /> recommendations than those included in the evaluation submitted to the Division on May 17, <br /> 2019, the operator must commit to inspecting the bulkhead on a weekly basis during operations <br /> to document conditions, including any increases in seepage or the development of any <br /> concentrated areas of flow. <br /> CMC Response: CMC commits to inspecting the Times Mine Bulkhead to document conditions, <br /> including any increases in seepage or the development of any concentrated areas of flow on a <br /> weekly basis during operations, until DRMS has reviewed and approved the new bulkhead <br /> evaluation based on the results of the proposed pumping test, which may include different <br /> recommendations than those included in the Deere & Ault Consultants evaluation of the Times <br /> Mine Bulkhead submitted on May 17, 2019. <br /> 5) The operator's response to Item no. 1(g) states the operator has discussed the potential for <br /> concrete degradation of the Times Mine Bulkhead with Deere & Ault and prefer to let them <br /> address the need to sample the water quality on a quarterly basis to evaluate the potential for <br /> concrete degradation of the bulkhead. <br /> Please be advised, until the Division has reviewed and approved the new engineer bulkhead <br /> evaluation based on the results of the proposed pumping test, and including different <br /> recommendations than those included in the evaluation submitted to the Division on May 17, <br /> 2019, the operator must commit to monitoring water quality in the Times Mine on a quarterly <br /> basis (for the sampling parameters approved in AM-01) to evaluate potential concrete <br /> degradation of the bulkhead, and submitting these results to the Division in the quarterly <br /> groundwater monitoring report. <br /> 4 <br />