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0 ameo <br />6.2.6 Non-Destructive Testing <br />Lone Star performed non-destructive seam testing on completed seams and geomembrane <br />repairs. Non-destructive testing for seams included pressure testing of fusion-welded <br />seams, and vacuum testing of extrusion welded seams and repairs. AMEC monitored and <br />documented the non-destructive testing. <br />Prior to pressure testing of fusion seams, Lone Star heat-sealed both ends of the air <br />channel between the two tracks of the double wedge weld. Lone Star then inserted a <br />pressure gauge in one end of the sealed channel. Lone Star pressurized the air channel to <br />approximately 30 pounds per square inch (psi) using an air pump. After pressure <br />stabilization, AMEC monitored the gauge for a minimum of five minutes. The maximum <br />allowable pressure drop was 3 psi. <br />Lone Star and AMEC verified fusion seam continuity before heat-sealing both seam ends, <br />completed pressure testing, and with the gauge left in place, cut the opposite end of the <br />seam. If the gauge pressure dropped to zero, the seam was determined to be continuous. <br />In cases where the seam was found to be discontinuous, the seam was subdivided into <br />shorter sections until continuous seam sections were located and passing pressure tests <br />were performed, or the outer edge of the seam was extrusion welded and vacuum tested. <br />If a pressure test failed, Lone Star checked the seam section for leakage, and repaired and <br />re-tested the seam. If Lone Star was unable to find the leak, the seam was divided into two <br />sections, with each section being tested to locate the area of concern. This subdivision <br />process was repeated until the leak location was identified. If the leak area was not located, <br />Lone Star reconstructed the seam, and then vacuum tested the repair. <br />Lone Star tested extrusion welded seam sections with a vacuum box. Prior to vacuum box <br />testing, Lone Star applied a soap and water solution to the seam section. The vacuum box <br />was then placed over the seam area and energized with a vacuum pump capable of <br />creating a vacuum of not less than 5 psi. Lone Star and AMEC observed the action of the <br />• vacuum on the seam for a minimum of ten seconds. Each consecutively tested seam length <br />AMEC Earth & Environmental, Inc. <br />2000 S. Colorado Blvd 2-1000 <br />Denver, CO 80222 <br />Tel 303-935-6505 <br />Fax 303-935-6575 www.amec.com <br />56