2019-08-23_REVISION - M1980244 (5)

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Cripple Creek&Victor Gold Mining Company Squaw Gulch VLF Phase 2A Part 1 ■ Record of Construction Report 475.0106.032 August 21,2019 K.2.1. The weld was inspected constantly for insufficient overlap, burnouts, or any other damage caused during the welding process. The CQA Monitor logged the welding machine and welding technician combination, the length of the seam, the direction the seam was welded, time of seaming, the welding machine temperature, and the welding machine speed. Destructive test samples were marked during fusion seaming and are discussed further in Section 3.5.6. Continuity conformance of the seam was also performed using pressure testing methods and is discussed further in Section 3.5.7. The Geomembrane Fusion Welding Summary is presented in Appendix K.3. 3.5.5. Geomembrane Extrusion Seaming At each construction bench, the deployed geomembrane was tied-into the previously placed geomembrane, overlapping a minimum of two feet. The tie-in was welded using extrusion welding methods. Any damage caused to the existing geomembrane, at the Phase 1 tie-in as it was exposed,was repaired by extending the overlap of new liner or by completely covering the damaged area with a patch. Prior to extrusion seaming activities, trial welds were performed for each welding machine and welding technician combination for each type of geomembrane. The trial seam logs are presented in Appendix K.2.2. As extrusion seaming was performed, proper techniques were verified including welding angle, grinding, and weld/welding rod cleanliness. The CQA Monitor logged the welding machine and welding technician combination,the length of the seam, the direction the seam was welded, time of seaming, the pre-heat temperature, and the welding temperature. Destructive test samples were marked during extrusion seaming and testing is discussed further in Section 3.5.6. All extrusion welded seams were vacuum tested and is discussed further in Section 3.5.8. The Geomembrane Extrusion Welding Summary is presented in Appendix K.4. 3.5.6. Geomembrane Destructive Testing During welding activities destructive test samples were marked for every 500 linear feet of seam for each welding type and each welding machine/welding technician combination. A 24-inch long by 12-inch wide sample was cut from the seam centered on the seam lengthwise. The sample was then cut in two halves. One half was archived by the CCLA Monitor to be tested later, if necessary.Ten 1-inch coupons were then cut from the remaining sample half. Five coupons were tested for shear strength and five coupons were tested for peel strength using a tensiometer. The different failure types and test codes for fusion and extrusion destructive testing are presented on Figures 3 and 4, respectively. All destructive testing was performed by Tetra Tech in the presence of the CQA Monitor.Two fusion destructive tests failed within the Squaw Gulch Phase 2A Part 1 area and the extent of the failure was delineated by obtaining samples before and after P:\Projects\0306.032 VLF2 Phase 2 CQA\1-REPORTS\Cert Report-Phase 2A Part 1\DRMS Comments\475.0106.032 CCV PHASE 2A Part 1 ROC REPORT_Revl.docx Page 16