2014-01-17_REPORT - M1980244 (3)

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Cripple Creek & Victor Gold Mining Company Phase 5 Slide Repair Final Report Quality Assurance Monitoring & Test Results January 14, 2014 Rim seven fusion seam destructive samples and two extrusion seam destructive samples of the primary geomembrane for the Phase 5 Slide Repair. ECA constructed approximately 3,489 lineal feet of fusion welded seams and 180 lineal feet of extrusion welded seams for the primary geomembrane. The specified frequency of destructive testing was one test per 500 lineal feet of weld. AMEC identified and ECA obtained destructive samples of the geomembrane panel seams at a frequency of one destructive test sample per 498 lineal feet of fusion welded seams, and one per 90 lineal feet of extrusion welded seams. The test frequencies exceeded project requirements. The summaries of destructive test results for fusion seams for the Phase 5 Slide Repair geomembrane are presented in Appendix J.5. The Geomembrane Panel As- Built Drawing presented in Appendix A shows the destructive test sample locations. 6.6 Non - Destructive Testing ECA performed non - destructive seam testing on completed seams and geomembrane repairs. Non - destructive testing for seams included pressure testing of fusion welded seams, and vacuum box testing of extrusion - welded seams and repairs. AMEC monitored and documented the non - destructive testing. Prior to pressure testing of fusion seams, ECA heat sealed both ends of the air channel between the two tracks of the double -wedge weld. A pressure gauge was inserted in one end of the sealed channel, the channel was pressurized to approximately 30 pounds per square inch (psi) using an air pump. After pressure stabilization, AMEC monitored the gauge for a minimum of 5 minutes. The maximum allowable pressure drop was 3 psi. ECA and AMEC verified fusion seam continuity before heat sealing both seam ends, completed pressure testing, and with the gauge left in place, cut the opposite end of the seam. If the gauge pressure dropped to zero, the seam was determined to be continuous. In cases where the seam was found to be discontinuous, the seam was subdivided into shorter sections until continuous seam sections were located and passing pressure tests were performed, or the outer edge of the seam was extrusion welded and vacuum box tested. If a pressure test failed, ECA checked the seam section for leakage, repaired any defects, and re- tested the seam. If ECA was unable to find the leak, the seam was divided into two sections, with each section being tested to locate the area of concern. This subdivision process was repeated until the leak location was identified. If the leak area was not located, ECA reconstructed the seam, and then vacuum tested the repair. ECA tested extrusion welded seam sections with a vacuum box. A soap and water solution was applied to the seam section then the vacuum box was then placed over s:\projects \1568 cc &v -ph v slide repair cqa \11.0 certification report\cc &v roc report. docx 15