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r � t <br /> A-3 <br /> 2.2 Well Evacuation <br /> After the static water level in a well is determined and prior to collection of a ground water <br /> sample, stagnant water will be removed from the well casing and the surrounding gravel pack <br /> by bailing, pumping, or with a vacuum truck. At least three casing volumes of water will be <br /> removed from each well from which a sample was collected. The volume of water in the casing <br /> will be determined from the known elevation of the water surface, the well bottom elevation (as <br /> measured when the well is installed), and the well diameter. <br /> If the well is bailed or pumped during purging, samples will be collected and field analyzed for <br /> pH, temperature, and specific conductance. The well will be considered stabilized when <br /> repeated readings of the following parameters are within the ranges indicated as follows: <br /> • Specific conductance ±10 percent of the reading range <br /> • pH ±0.1 pH unit <br /> • Temperature ±0.5° C. <br /> After stabilization, and after at least three well volumes are evacuated, a sample will be collected <br /> for analysis. The field container used for well stabilization measurements, and the pH, <br /> temperature, and conductivity probes will be rinsed between wells with deionized water. <br /> All purge water will be containerized and properly handled and documented for disposal. If the <br /> containers are stored on site, a label specifying the date of purging, source, and the known or <br /> suspected nature of the contents will be affixed to each container. <br /> 2.3 Sample Collection, Preservation, and Handling <br /> After purging, a new polyethylene disposable bailer will be used to collect samples for analysis. <br /> The bailer is attached to a new disposable rope and lowered slowly into the water to avoid <br /> agitation of the collected sample. Containers for volatile organics analyses will be filled <br /> completely so that no airspace remains in the vial after sealing. <br /> All sample containers will be prewashed and prepared at the analyzing laboratory in accordance <br /> with quality assurance/quality control protocols of the laboratory. Only sample containers <br /> appropriate for the intended analyses will be used. <br /> LRPT008.MAF <br />