COMPLIANCE INFO_2005-2012 - Laserfiche WebLink

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Dec 16 04 04:51p CG&L CR 916- 91-1177 p.4 Method Description The process is described in the following steps: • Preparation • Probe Array Installation • Inoculation • Sample Collection • Sample Analysis • Reporting Preparation Upon arrival at the site, the Tracer crew reviews the tank information that has been made available and uses this information to plan the installation of the sampling probe array. If as built plans or site plans have not been made available the crew inspects all accessible portions of the system to learn as much as possible about the location of all UST system components. If the site is under remediation, soil vapor extraction systems, air sparging systems and bio -venting systems must be turned off during the test. Probe Array Installation Sampling probes consisting of %" schedule 40 PVC are installed within ten horizontal feet of all possible leak locations. In situations where tank pits and piping trenches do not contain engineered backfill (pea -gravel), the sampling probes are installed within five horizontal feet of all possible leak locations. Tank probes are installed along the outer long -side of each tank, generally at a depth within two feet of the tank bottom (or just above the water table if applicable). Additional probes may also be installed near appurtenances along the tank ridge, but these are not required, but highly recommended in order to assist in identifying the source of potential vapor leaks. Piping probes are placed along the product distribution, vapor recovery and vent piping trenches, generally at a depth of two feet below grade. Probes are installed by coring a hole in the pavement and inserting a sampling probe into the excavation zone of the tank or pipe using soft excavation techniques. The top of each probe is fitted with a PVC sampling cap that will be used later for soil vapor extraction.