2021-07-21_REVISION - M2012032 (2)

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Lk.�ka} Srt��rR4rvFs characterization of the concentrates. Additionally, if concentrate materials are significantly changed, also provide updated SDS of the new representative material at that time. Response: The mine commits to suppling a SDS of the Zinc concentrate and the Lead concentrate to the Division within 30 days of the production of'the,first shipment. 0S:1111 also will develop an updated SDS.should the chemistry ofthe concentrates change significantly, although this is not expected. 4. The response to Item 29 of Adequacy review #1 is noted. However, if the tailings lines were to break, the material would not have passed through the filter press to remove excess moisture as required by the Tailings and Waste Rock Management Plan prior to final placement in the Tailings Storage Facility. if the lines were to break, the spilled tailings would need to be added back to the system until such time that they could be returned to the filter press and properly dewatered in preparation for final placement. Please Commit that no tailings will be placed in either of the Tailing Storage Facilities until they have been properly dewatered to the expected range of 13%to 18%moisture,or 82-87%solids in accordance with the Tailings and Waste Rock Management Plan. Response: No tailings will be placed in either of the TVs until the tailings have been properly dewatered to the expected moisture range pf 13%- 18% in accordance with the Tailing& Waste Rock Management Plait. The tailings will be left in the tailings bal'of the mill to dewater before being placed in a TV. 5. Table 9 does include the list of sumps, their volumes and where they report to, however no drawing references were provided. Please provide a drawing number reference so that the detai Is of the sumps can be verified. Response: Please see the attached updated Table 9. 6. Item 31 b of adequacy review#I was in reference to the baseline characterization testing required for tailings prior to final placement in the Tailings Storage Facility, and the commitment to hold the tailings in a secure location until all testing could be completed. During the Jul 2, 2021 meeting, it was agreed that a temporary clay liner would be installed in the Revenue Tailings Storage Facility for temporary holding until the baseline characterization tests could be completed. Please provide details including a written commitment to the temporary storage of tailings on the compacted clay liner, a brief summary of the construction of the liner, a map showing the location of the liner, and the approximate volume of tails to be placed on the pad. Once the tests have been conducted and reviewed by the Division a determination on the final placement will be made. Response: The mime commits to storing tailings on a woven clot•liner until baseline characterization testing has been completed and results cure available. The liner is a geosvnthetic clay liner—the same product that was used to line the passive water treatment system. The liner will be placed in the east end of the Revenue TSF cis shown on Mapl. The area below the lines' will be leveled before the liners are placed. It is estimated that there will be between 400 and 700 cubic yards of tailings stored on the liner. Once tests have been conducted and reviewed by the Division,far approval, the tailings will be moved to_final placement. 21r> :� _ ,