2009-12-21_REVISION - M1980244 (28)

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Cripple Creek & Victor Gold Mining Company Cresson Project Quality Assurance Monitoring and Test Results Liner Recertification December 17, 2009 from the SLF and to uniformly condition the material to project specifications prior to stockpiling at the South Cresson Clay process stockpile. The SLF was compacted to a minimum thickness of 12 inches by a smooth -drum vibratory compactor. AMEC observed SLF depth verification tests performed by Ames to confirm appropriate fill depth. Any areas that were found to be deficient in thickness were reworked and retested until the area met specifications. The SLF depth verification is discussed in Section 4.2.3. SLF was moisture - conditioned and compacted as needed to meet project specifications. The minimum SLF density was 95 percent of the maximum dry density at optimum moisture content to 3 percent wet of optimum as determined by standard Proctor tests performed by AMEC. Areas of the SLF that initially failed to meet the moisture - density requirement were moisture - conditioned, if necessary, and re- compacted to achieve the required compaction to project specifications. Prior to geomembrane deployment on the SLF, Ames proof - rolled, compacted, and hand - worked the fill surface to be free of desiccation cracks and abrupt grade changes. AMEC then inspected the surface. Sharp or angular stones greater than 0.75 inches in diameter were removed from the finished surface. AMEC approved fill surfaces prior to release to Lonestar (Geomembrane Subcontractor to Ames) for deployment. AMEC provided formal subgrade approval prior to geomembrane deployment. The subgrade acceptance forms are presented in Appendix F. 2.3 Geomembrane Liner A single geomembrane composite liner system was installed in the recertified areas for ore storage on the VLF. The composite liner system consists of a minimum of 12 inches of compacted SLF overlain by a single layer consisting of 100 -mil single sided texture LLDPE geomembrane. Ames anchored geomembrane at the limits of the Phase IVa recertification area in a 3 feet deep by 2 feet wide anchor trench. Ames backfilled the anchor trenches with suitable anchor trench backfill material. Ames placed anchor trench backfill in maximum 12- inch -thick compacted lifts. Anchor trench backfill was compacted with "Jumping Jacks." The geomembrane liner overlapped and was extrusion welded to the Phase IV VLF liner system, as detailed in Phase 5 IFC Drawing No. A250. The geomembrane as -built panel layouts are shown on Figures 4 and 5. Upon completion, a 2 -foot layer of DCF was then placed over the geomembrane to project specifications. S: \PROJECTS \1125E CCV COA \H2 - DESIGN\LINER RECERTIFICATION REPORT\REPORT BODMA MONTIORING AND TEST RESULTS LINER 6 RECERTIFICATION.DOC