2014-02-07_REPORT - M1980244 (3)

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Cripple Creek & Victor Gold Mining Company PSES Pipe Rack Liner Extension Final Report ameO Quality Assurance Monitoring &Test Results February 4, 2014 6.5 Destructive Testing AMEC selected destructive test locations based on ECA's completion of approximately 748 lineal feet of welding for the primary geomembrane, various working conditions, and on seaming observations (e.g., suspicion of a defective weld). AMEC obtained and tested two fusion seam destructive samples and two extrusion seam destructive samples of the primary geomembrane for the PSES Pipe Rack Liner Extension. ECA constructed approximately 502 lineal feet of fusion welded seams and 246 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 from the primary geomembrane panel seams at a frequency of one destructive test sample per 251 lineal feet of fusion welded seams, and one per 123 lineal feet of extrusion welded seams. The test frequencies exceeded project requirements. All destructive test results met or exceeded requirements as presented in the Technical Specifications. The summaries of destructive test results for fusion seams for the PSES Pipe Rack Liner Extension geomembrane are presented in Appendix J.5. Sheet 2 of 2 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 tested. If a pressure test failed, ECA checked the seam section for leakage, and repaired and re- tested the seam. If ECA was unable to find the leak, the seam was divided into two