2018-06-04_REVISION - M1980244 (5)

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2) Figure 2: Figure 2 shows a 42 foot offset as a limit "of additional ore removal (to with (sic) 2' of geomembrane surface as determined by field conditions." Subsequent discussions between the Division and CC&V have set the ore/drain cover fill (DCF) removal to a distance of 50 feet beyond any discovered liner damage. Please confirm this 50 foot commitment to ore/DCF removal beyond observed damage to confirm the limits of liner damage. A minimum of one competent panel (a panel showing no visible signs of damage from the slough) will be exposed beyond the extent of liner visibly damaged by the December 16 slough. Ore and DCF will be removed from the panel, allowing liner integrity tests to be performed in these areas.If the liner integrity tests fail to meet technical specifications,ore and DCF from the adjacent panel will be removed to allow for additional integrity tests. 3) Criteria for undamaged liner: The Division understands observations and/or tests will be conducted to determine the extent of damaged liner 50 feet away from geomembrane with observable damage. It is also understood that the LLDPE material was selected in order to take advantage of its elongation properties and that the amount of"stretch" experienced by the liner surrounding the damaged liner will be critical to assessing whether given portions of the geomembrane are damaged or not. Please describe the test(s) and acceptance criteria for determining whether or not "undamaged" geomembrane is acceptable. Geomembrane samples will be taken along the perimeter panels between the 9650' and 9750' benches and sent to an independent lab for integrity testing to verify the liner meets the project specifications. No ore will be placed in this area until the integrity test proves the geomembrane liner meets project technical specifications. 4) 9,750 Bench Seam Integrity Verification: The Division understands during the original VLF2 liner construction a bench with an anchor trench for the geomembrane liner was constructed at the 9750 level, then subsequent liner installation seem welded geomembrane installed above the 9750 level to the liner exposed above the anchor trench. Please provide a discussion as to how the integrity of this seem will be verified and recertified. The 9750' bench seam will be replaced and certified with the deployment of the new geomembrane liner. 5) 5) 10,050 Level:In the Division's inspection report dated March 15, 2018, Photo 6 identifies an area above the now known liner damage where material from the mill has been placed reportedly by pushing it over the edge, allowing this material to move downward across the DCF, essentially parallel to the liner slope (see image below). Please address how the liner under this mill material will be verified to be undamaged. To provide safe access, and to minimize the risk of inadvertently impacting the liner,CC&V will address this area once the current stacking plan advances to this elevation. This will allow equipment access,as well as the ability to buttress the material. Once the buildout reaches this area,CC&V will remove material down to the DCF and perform an inspection of the liner via potholing, as proposed in the initial TR100 submittal.