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Forward Compost Facility Stormwater Improvements <br />02778 16 HDPE GEOMEMBRANE <br />tunnel created by the weld. iii. Energize the air pump to a minimum pressure of 30 psi or 1/2 psi per mil of liner thickness, whichever is greater, close valve and sustain pressure for at least 5 minutes. iv. If loss of pressure exceeds 2 psi (10 mm mercury), or otherwise approved, or does not stabilize, locate faulty area and repair in accordance with repair procedures described in this specification. v. Puncture opposite end of seam to release air. If blockage is present, locate and test seam on both sides of blockage. vi. Remove needle or other approved pressure feed device and seal the penetration holes. 4. Spark Testing for penetrations or other difficult areas not accessible for vacuum testing. a. Equipment and Materials. i. 24 gauge copper wire. ii. Low-amperage electric detector, 20,000 to 30,000 volt, with brush-type electrode capable of causing visible arc up to inch from copper wire. b. Procedures. i. Place copper wire within inch of the edge of extrusion seam or clamp seal. ii. Pass electrode over seam or clamp area and observe for spark. If a spark is detected perform a repair. 5. Destructive Testing. a. Location and Frequency of Testing. i. The QA/QC CONSULTANT shall collect destructive test samples at a minimum frequency of one test location per 500 feet of seam length. ii. Determine test locations during welding. Locations may be prompted by suspicion or excess crystallinity, contamination, offset welds, or suspected defect. The QA/QC CONSULTANT will be responsible for choosing the locations and will not notify installer in advance of selecting locations where weld samples will be taken. iii. The QA/QC CONSULTANT may increase the test frequency based on marginal results. b. Sampling Procedures. i. The GEOSYNTHETICS CONTRACTOR shall cut samples at locations designated by the QA/QC CONSULTANT as the welding progresses. Verify that laboratory test results have been obtained before the geomembrane is covered by another material. ii. The QA/QC CONSULTANT will number each sample and mark sample number and location in compliance with the CQA program. iii. The GEOSYNTHETICS CONTRACTOR shall immediately repair all holes in the geomembrane resulting from destructive test sampling. Repair in accordance with repair procedures