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' Monitoring and Sampling Procedures <br /> FERNANDO'S PLACE <br /> ' 1201 South Center Street, Stockton, California <br /> STATIC WATER LEVEL MEASUREMENTS <br /> Before sampling and during groundwater monitoring, static water levels are measured <br /> ' using an electricwater level indicator. Water level data is recorded to the nearest 0.01-foot <br /> from a reference point marked on the top of the PVC well casing. <br /> WELL PURGING <br /> ' Subsequent to measurement of depth to water and prior to sampling, each well is purged <br /> to ensure samples are representative of the formation, rather than standing water in the <br /> well casing. Wells are purged using a Waterra inertial pump and dedicated 5/8-inch plastic <br /> ' tubing. <br /> Wells are purged until a minimum of three casing-water volumes are removed from the well <br /> ' and/or the field-measured ground water parameters (pH, temperature, and conductivity) <br /> are stabilized. However, if a well is purged dry prior to evacuating three casing volumes, <br /> a sample is collected following 80 percent recovery of ground water within the well, or after <br /> ' a minimum of one hour, but within eight hours, of well purging activities. <br /> Field data and logs are provided in Appendix C. <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 the <br /> inertia pump is either dedicated to each well point or changed at each sampling event, <br /> thereby minimizing cross contamination due to sampling devices. Samples are drawn and <br /> ' collected in such a manner that agitation and exposure of the groundwater to the <br /> atmosphere is minimal. <br /> SAMPLE HANDLING <br /> tGround water samples are collected into laboratory-supplied 40-ml volatile organic analysis <br /> (VOA) vials without preservative and, if appropriate, one-liter amber glass containers <br /> without a preservative; the samples are collected with no visible air bubbles present in the <br /> ' vials after filling and capping. <br /> Advanced GeoEnvironmental,Inc. <br /> t <br />