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Monitoring and Sampling Procedures <br />LEVAND — BRIGHT PROPERTY <br />3 East Eleventh Street, Tracy, California <br />STATIC WATER LEVEL MEASUREMENTS <br />Before sampling and during groundwater monitoring, static water levels will be <br />measured at all wells using an electric water level indicator. Water level data is recorded <br />to the nearest 0.01-foot from a reference point marked on the top of the PVC well <br />casing. <br />WELL PURGING <br />Subsequent to measurement of depth to water and prior to sampling, each well is <br />purged to ensure samples are representative of the formation, rather than standing <br />water in the well casing. Wells are purged using a Waterra inertial pump and dedicated <br />%-inch plastic tubing or a disposable polyethylene bailer. <br />Wells are purged until a minimum of three casing-water volumes are removed from the <br />well and/or the field-measured ground water parameters (pH, temperature, and <br />conductivity) are stabilized. However, if a well is purged dry prior to evacuating three <br />casing volumes, a sample is collected following 80 percent recovery of ground water <br />within the well, or after a minimum of one hour, but within eight hours, of purging <br />procedures. <br />SAMPLE WITHDRAWAL <br />Water samples are collected from each monitoring well using either an interia pump with <br />dedicated plastic/Teflon tubing or a disposable polyethylene bailer. Bailers are disposed <br />of after a single use (sample) and require no decontaminating; plastic tubing used with <br />the inertia pump is either dedicated to each well point or changed at each sampling <br />event, thereby minimizing cross contamination due to sampling devices. Samples are <br />drawn and collected in such a manner that agitation and exposure of the ground water <br />to the atmosphere is minimal. <br />SAMPLE HANDLING <br />Ground water samples are collected into laboratory-supplied 40-ml volatile organic <br />analysis (VOA) vials with preservative and, if appropriate, one-liter amber glass <br />containers without a preservative; the samples are collected with no visible air bubbles <br />present in the vials after filling and capping. Following collection, samples are <br />appropriately labeled, placed on ice, and kept in a cooler until delivered to a California