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Comment 8: Please provide the maximum time to discover an upset condition and the <br /> maximum time to shut down the leach circuit. <br /> Response 8: If slurry failed to flow through the circuit resulting in the overtopping <br /> of a tank, CC&V would starve the discharge pumps in about 1 hour(assuming full <br /> flow is spilling),which would set-off an alarm in the control room. If a partial spill <br /> occurred the duration would be longer but with less flow, leading to a maximum <br /> undetected spill time of approximately 4 hours. This timeframe is predicated on the <br /> time between operator check-ups on proper functionality of the HGM process <br /> system. This timeframe does not consider other mine personnel who work in that <br /> area that would likely identify and provide notification to the supervisor on shift. <br /> Comment 9: TR-81 proposes the secondary,containment capacity will be re-established <br /> within 7 days after an upset condition within the vat leach tank circuit. Please discuss the <br /> active leaching circuit and milling operations during this time when process slurry has <br /> consumed all or a portion of the secondary containment. Please clarify if these same <br /> processes will be operational if the secondary containment capacity is not re-established <br /> within 7 days. <br /> Response 9: All process functions will be operational during the time of any <br /> collection of process slurry in the secondary containment area. Process slurry will <br /> be removed as quickly as possible and is expected to occur within two operating <br /> shifts. <br /> Comment 10: The secondary containment clean out schedule,proposed within the TR-81, <br /> states the process slurry will be removed from the secondary containment. Please clarify <br /> that all material within the secondary containment, including precipitation, will be <br /> removed to ensure that the entire capacity has been re-established. <br /> Response 10: All material within the secondary containment and precipitation <br /> falling within the secondary containment area will be removed to ensure the entire <br /> capacity has been re-established. Precipitation falling within the secondary <br /> containment is pumped back into the mill process circuit for make-up water. CC&V <br /> would like to note that the sumps are automatically pumped when water or process <br /> slurry is present in the secondary containment area. <br /> Comment 11:Please clarify how material will be removed from the secondary containment. <br /> Based on previous conversations, the Division understands that Leach Area Sump Pump No. <br /> 1 and No. 2 will be used to pump the slurry back into the circuit. Please discuss how power <br /> to these pumps will be maintained during a power outage. <br /> Response 11: In the event of a power outage,the entire mill and leach area sump No. <br /> 1 and No. 2 will be powered automatically by seemless transition to onsite diesel <br /> back-up generators.In effect, electrical power is never interrupted and the sumps <br /> are always operational. <br />