2020-07-08_REVISION - M1980244 (20)

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Cripple Creek&Victor Gold Mining Company Squaw Gulch VLF Phase 2A Part 3 lam Record of Construction Report ■ 475.0106.032 July 2,2020 2.4. Soil Liner Fill Approximately 11,226 cy of SLF was placed within the Squaw Gulch VLF Phase 2A Part 3 area.The as-built SLF surface is presented in Soil Liner Fill As-Built record of construction drawings. Materials from the Cameron borrow, WHEX pit and ECOSA borrow were processed through a custom-designed rotary mill and screen in order to remove oversized rock and uniformly condition the material. After processing, the SLF was stockpiled in designated stockpiles around the site. The contractor used 30- and 40-ton articulated haul trucks to haul SLF from the local stockpiles to the Squaw Gulch VLF Phase 2A Part 3 footprint. The material was spread using LGP dozers equipped with GPS,and moisture conditioned in place by tandem-axel water trucks and laborers. A 12- and 19-ton smooth drum vibratory compactor, track-mounted skid steer with roller attachment, and excavator with smooth drum roller attachment were utilized to compact the SLF to a minimum thickness of 12 inches. The specified minimum density was 95 percent of the maximum dry density at minus 2 percent to plus 3 percent of optimum moisture content as determined by American Society for Testing and Materials (ASTM) D698. Laboratory testing, moisture content verification, nuclear density testing, depth verification, and visual inspection of the SLF were performed by the CQA Monitor prior to approval for geomembrane deployment. If deficient areas of the SLF were encountered, the area was reworked and retested until the area was compliant with the project Technical Specifications. All SLF was inspected and approved by the CQA Monitor, CC&V, Tezak, and Tetra Tech prior to geomembrane deployment. SLF acceptance is discussed further in Section 3.2.3 and Section 3.4.2. SLF acceptance forms are provided in Appendix E. 2.5. Geomembrane Tetra Tech installed approximately 303,105 square feet of 80 mil LLDPE DSMS geomembrane within the Squaw Gulch VLF Phase 2A Part 3 area as shown on Record Drawing No. 5. The geomembrane used in Phase 2A Part 3 was from the geomembrane stockpile from the 2019 construction season as well as from the December 2019 delivery. The edge of geomembrane along the eastern end of the project limits, which will tie in with future construction phases, was protected by burying it within the SLF. Forklifts were used to transport and deploy the geomembrane panels parallel to the slopes to minimize stress on seams. Double-wedge fusion welding was the primary method of geomembrane seaming. Extrusion welding methods were used to perform tie-in seaming, defect repairs, and detail activities. Continuity conformance of fusion welded seams was performed using pressure testing methods, while extrusion welded seams and repairs were non- P:\Projects\0106.032 VLF2 Phase 2 CQA\1-REPORTS\Cert Report-Phase 2A Part 3\475.0106.032 CCV PHASE 2A Part 3 ROC REPORT.docx Page 5