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GR Field Methods and Proceduies <br /> Groundwater Monitoring and Sampling <br /> Decontamination Procedures <br /> All physical parameter measuring and sampling equipment are decontaminated prior to sample collection using <br /> Alconox or equivalent detergent followed by steam cleaning with deionized water During field sampling, equipment <br /> placed in a well are decontaminated before purging or sampling the next well by cleaning with Alconox or equivalent <br /> detergent followed by steam cleaning with deionized water <br /> Water-Level Measurements <br /> Prior to sampling each well, the static water level is measured using an electric sounder and/or calibrated portable oil- <br /> water interface probe Both static water-level and separate-phase product thickness are measured to the nearest <br /> f0 01 foot The presence of separate-phase product is confirmed using a clean, acrylic or polyvinylchloride (PVC) <br /> bailer, measured to the nearest ±0 01 foot with a decimal scale tape The monofilament line used to lower the bailer <br /> is replaced between borings with new line to preclude the possibility of cross-contamination Field observations (e g <br /> product color, turbidity, water color, odors, etc ) are noted Water-levels are measured in wells with known or <br /> suspected lowest dissolved chemical concentrations to the highest dissolved concentrations <br /> SMple Collection and Labeling <br /> A temporary PVC screen is installed in the boring to facilitate a grab groundwater sample collection Samples of <br /> groundwater are collected from the surface of the water in each well or boring using the teflon bailer or a pump The <br /> water samples are then gently poured into laboratory-cleaned containers and sealed with teflon-lmed caps, and <br /> inspected for air bubbles to check for headspace The samples are then labeled by an adhesive label, noted in <br /> permanent ink, and promptly placed in an ice storage A Chain-of-Custody Record is initiated and updated <br /> throughout handling of the samples, and accompanies the samples to the laboratory certified by the State of California <br /> for analyses requested <br /> i <br /> A-3 <br />