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June 24,2003 -43- 003-2203.7 <br />• testing of extrusion welded seams and repairs. Golder monitored and documented the non-destructive <br />testing. <br />Prior to pressure testing of fusion seams, Poly-Flex heat-sealed both ends of the air channel between <br />the two tracks of the double wedge weld. Poly-Flex then inserted a pressure gauge in one end of the <br />sealed channel. Poly-Flex pressurized the air channel to approximately 30 pounds per square inch <br />(psi) using an air pump. After pressure stabilization, Golder monitored the gauge for a minimum of <br />five minutes. The maximum allowable pressure drop was 3 psi. <br />Poly-Flex and Golder verified fusion seam continuity before heat-sealing both seam ends, completed <br />pressure testing, and with the gauge left in place, cut the opposite end of the seam. If the gauge <br />pressure dropped to zero, the seam was determined to be continuous. In cases where the seam was <br />found to be discontinuous, the seam was subdivided into shorter sections until continuous seam <br />sections were located and passing pressure tests were performed, or the outer edge of the seam was <br />extrusion welded and vacuum tested. <br />If a pressure test failed, Poly-Flex checked the seam section for leakage, and repaired and re-tested <br />• the seam. If Poly-Flex was unable to find the leak, the seam was divided into two sections, with each <br />section being tested to locate the area of concern. This subdivision process was repeated until the <br />leak location was identified. If the leak area was not located, Poly-Flex reconstructed the seam, and <br />then vacuum tested the repair. <br />Poly-Flex tested extrusion welded seam sections with a vacuum box. Prior to vacuum box testing, <br />Poly-Flex applied a soap and water solution to the seam section. The vacuum box was then placed <br />over the seam area and energized with a vacuum pump capable of creating a vacuum of not less than <br />5 psi. Poly-Flex and Golder observed the action of the vacuum on the seam for a minimum of ten <br />seconds. Each consecutively tested seam length was overlapped a minimum of 3 inches. If soap <br />bubbles appeared, Golder marked and documented the leak location. Poly-Flex then repaired the leak <br />and vacuum tested the repair. This procedure was also followed to test extrusion repairs and <br />extrusion patches. <br />The seam non-destructive test summaries (fusion pressure tests and extrusion vacuum tests) for the <br />lower and upper PSSA geomembrane layers are presented in Appendix K-7 and L-7, respectively. <br />• <br />~:~oo~zzasoaoou~mCmrss.+osomamzma.adoa.ov~.uaepmc Golder Associates <br />