2009-07-15_REVISION - M1980244 (23)

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• • • Cripple Creek & Victor Gold Mining Company Cresson Project Quality Assurance Monitoring and Test Results Load Out Bin Relocation July 7, 2009 ameO Ames graded existing slopes and placed SF so that final slopes were no steeper than 2.5H:1V. Prior to fill placement, the in-situ material was scarified to a depth of approximately 6 inches. SF was compacted with a minimum of four passes by a smooth drum vibratory compactor. Ames placed a small amount of SF (less than 2000 CY) for site grading. 2.3 Subgrade Preparation Prior to SLF placement, Ames moisture conditioned and compacted the entire surface of the LOB with a smooth drum vibratory compactor. The quality of the finished surface was then maintained until SLF was placed. 2.4 Soil Liner Fill Based on neat-line survey, Ames placed and compacted approximately 1,245 cubic yards of SLF in the LOB footprint. Figure 5 presents the as-built surface of the SLF. Ames processed the SLF for the LOB construction previously during phase IV construction. Ames worked the borrow material through a rotary mill and screen to remove oversized material from the SLF and to uniformly condition the material prior to stockpiling at the Arequa process stockpile. Ames began placing SLF on the LOB pad in April 2009. 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 4.2.4.3. 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. 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 G. SAPROJECTS11125E CCV CQA\H3 - CONSTRUCTIOMLOB CERT REPORT\REPORT BODY\LOB CERT REPORT 2009.07.07.DOC 7