2019-09-30_REVISION - M1980244 (5)

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Cripple Creek&Victor Gold Mining Company ■ Squaw Gulch VLF Phase 2A Part 2 ■ Record of Construction Report 475.0106.032 September 30,2019 where needed. Compaction of the subgrade was performed in accordance with the applicable developed method specifications, presented in Appendix D, for a 12-ton vibratory sheepsfoot drum compactor. The CQA Monitor inspected and approved the finished subgrade surface prior to SLF placement. 2.4. Leak Detection Trench Approximately 387 linear feet of leak detection trench was constructed within the Squaw Gulch VLF Phase 2A Part 2 limits in accordance with the project Technical Specifications. The Phase 2A Part 2 leak detection trench is presented in Record Drawing No. 5. Detail N on IFC Drawing A68 shows the typical leak detection trench section. Per Detail N, a minimum one foot by one-foot trench was excavated and lined with 40 mil smooth LLDPE geomembrane. The geomembrane was installed in long strips with a 5-foot overlap and was overlain by a 12 oz/ydz non-woven geotextile. A 4-inch diameter perforated corrugated polyethylene pipe (CPeP) was then placed in the trench. The trench was backfilled with Leak Detection Fill (LDF) and the geotextile was wrapped around the fill with a minimum 1-foot overlap. A minimum slope of 0.5 percent was maintained along the entire length of the trench. The CQA Monitor observed all leak detection trench installation to date. The Squaw Gulch VLF Phase 2A Part 2 leak detection trench was constructed by installing approximately 1,935 square feet of 40 mil smooth LLDPE geomembrane, 1,935 square feet of 12 oz/yd2 non-woven geotextile, 387 linear feet of 4-inch CPeP and 14 cy of LDF. 2.5. Soil Liner Fill Approximately 64,430 cy of SLF was placed within the Squaw Gulch VLF Phase 2A Part 2 area.The as-built SLF surface is presented in Record Drawings No. 1 through 4. Materials from the Cameron borrow and WHEX pit 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 2 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 P.\Projects\Cert Report-Phase 2A Part 2\475 0106 032 CCV PHASE 2A Part 2 ROC REPORT.docx Page 4