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Responses to 3/25/11 Comments from Division of Reclamation, Mining and Safety <br />Comment 1. The proposed design requires a minimum five foot cover everywhere. Given the expected <br />poor quality of water transmitted in the pipeline, how are leaks to be detected. Please note a small leak <br />over a long enough period of time could pose environmental problems. <br />a. CMC's response discusses "several appurtenances and mechanisms to prevent, detect, and mitigate <br />leakage along the pipeline should it occur". The fact that the pipeline "is not expected to leak" does not <br />prevent it from leaking. The plan to remotely monitor operating pressures in the suction and discharge <br />headers inside the proposed pump station from the new mill control room (including an alarm) should <br />identify significant problems or leaks unless they occur very near the mill process water storage tank. <br />DRMS is less certain of the effectiveness of the granular pipe bedding to convey leakage back to the <br />proposed Vault #3 at Station 13+00. The proposed design includes several thousand feet of pipeline with <br />a-grade-of-040-percent or less:-Station 10+93.37to-30+26.50 (0.10916); Station 33+27.33 to 47+45.69 <br />(0.10%), Station 76+90.59 to 87+52.28 (-1.43%), and Station 87+52.28 to 118+34.61 (0.09%). It should be <br />noted that any leakage collected in the granular pipe bedding above Station 76+90.59 (invert elevation <br />11,142.737 ft) will pond in the bedding from that point to approximately Station 127+00 (approximately <br />5,010 feet of pipe length) where the pipeline invert again exceeds elevation 11,143 ft, unless the pipe <br />trench subgrade is more permeable than the granular bedding. DRMS recommends CMC not rely on the <br />granular pipe bedding to convey leakage back to Vault #3. If CMC wants to use the pipe bedding material <br />to collect and control leakage, additional vaults with sump and sump pumps should be considered. <br />Response: Climax recognizes that Valve Vault 3 may not be effective for collecting leakage along the <br />entire length of the pipeline. The intent of the original response to DRMS was to illustrate that if water <br />does collect in the granular pipe bedding above Station 13+00, it will not flow down the pipe gradient <br />beyond Valve Vault 3. Please note that any leak in the pipeline above Station 13+00 will be contained in <br />Climax's process water system. As examples, if a leak were to occur above Station 76+50, water would <br />flow into the camp drainage system or the Robinson TSF. If a leak were to occur between Station 11+80 <br />and Station 76+50, water would flow into the Robinson Lake. If a leak were to occur below Station <br />11+80, water would flow into the seepwater collection pond below Robinson Dam. A leak that does not <br />emanate on the ground surface would either be contained in the pipe bedding or migrate to one of the <br />seepwater collection systems which are located below Robinson Dam, 3Dam, and 5Dam. <br />As a best management practice Climax currently conducts daily visual inspections of all active pipelines <br />during each shift, and will include inspections of the entire reclaim pipeline route during each shift where <br />that pipeline becomes operational. These frequent visual inspections provide for immediate detection <br />and response should a leak occur. Together with the other protective measures described in the original <br />response to DRMS for the reclaim line, the visual inspections are a key component to a comprehensive <br />monitoring/mitigation system to prevent potential environmental impacts. <br />Climax Mine has an excellent environmental record. Its ongoing commitment to environmental <br />protection has been acknowledged by the Division through the reclamation awards it has received. This <br />commitment also will be maintained at its currently high level upon resumption of mining and milling <br />activities. <br />Comment 2. Based on a vague familiarity with the site, the Division is concerned about the buried <br />pipe from about Station 37+00 to 47+45 (ref. Drawing 540-L-PN-002). Ponded water has been observed <br />in this area in the past, presumably seepage collection from Robinson TSF. Please address the potential <br />1