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Reviewed by David Rabb • Praxair service,Inc.QA Approved by Randy Golding Tracer Tight® Update 10-14-04 Version V-4 Description The process is described in the following steps: • Preparation • Probe Array Installation • Confirmation Test • Inoculation • Leak Simulation • Sample Collection • Analysis • Spill Bucket Test • Reporting Preparation All necessary permits must be acquired and appropriate notices to local regulators must be given prior to arrival at the site. Upon arrival, the 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. Groundwater measurements are to be taking within the tank excavation zone. Probe Array Installation Vertical PVC sampling probes are installed within eight horizontal feet of all possible leak locations (a maximum of 15 feet apart). In situations where tank pits and piping trenches do not contain engineered backfill (sand or pea-gravel), the sampling probes are installed with a maximum 10-foot spacing. Tank probes are installed along the side of each tank, generally at a depth centered on the tanks. Maximum probe depth is 15 feet (or just above the water table if applicable). Additional probes are installed near any appurtenances along the tank ridge where a containment sump is not present. Piping probes are placed along the product distribution,vapor recovery and vent piping trenches,to one half the depth of the piping or until the end of the probe is within engineered backfill. Probes are generally installed at a depth of 1 to 1.5 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 install technique. Lowering and/or wiggling the probe into the backfill as the backfill material is being evacuated through the center of the probe by a high volume vacuum pump, completes the soft install. Upon installation, the top of each probe is fitted with a PVC sampling cap that will allow access for the collection of samples. Confirmation Test Confirmation Test (Pre-certification tightness test) is completed before the system is inoculated. The test is used to confirm the tightness of all the accessible fittings. This is done to ensure that the facility is tight before adding the tracer. A repair technician should be on site with all tools and parts to complete repairs to any and all components that are accessible. The technician should be qualified/certified to program and operate the electronics controlling the fueling system. Inoculation Inoculation is the process of adding chemical tracer to the product in the system to be tested. Product is inoculated with a predetermined amount of tracer, though the fill riser. Tracer is mixed by circulating the product using the turbine pump and a tracer mixing apparatus or by adding product to the tank. Once sufficient amount of tracer labeled product has been moved through each dispenser, the product is tested at each dispenser to confirm that tracer is present. By keeping the dispenser nozzle inside a receiving container, additional product is pumped into the container to push tracer labeled vapors through the vapor return piping back to the tank. The tracer/vapor mixture is then pushed from the UST out to the vent riser into a container of sufficient size that the tracer/vapor mixture has displaced the entire volume of the vent piping. The concentration of the tracer in the receiving container is then measured. THIS INFORMATION IS THEPROPERTY OFPRAXAIR SERVICE,INC 2 of