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r=' Groundwater Sample Collection <br /> After wells are purged, or not purged, according to TSR instructions, samples are collected for k <br /> laboratory analysis. For wells that have been purged using conventional pump or bail methods, <br /> sampling is conducted after the well has recovered to 80 percent of its original volume or after F <br /> two hours if the well does not recover to at least 80 percent. If there is insufficient recharge of <br /> water in the well after two hours, the well is not sampled. ' <br /> Samples are collected by lowering a new, disposable, lh-inch to 4-inch polyethylene.bottom-fill <br /> bailer to just below the water level in the well. The bailer is retrieved and the water sample is E <br /> carefully transferred to containers specified for the laboratory analytical methods indicated by f <br /> N <br /> the TSR. Particular care is given to containers for volatile organic analysis (VOAs) which <br /> require filling to zero headspace and fitting with Teflon-sealed caps. F <br /> After filling, all containers are labeled with project number (or site number), well designation, 3 <br /> sample date, and the samplers initials, and placed in an insulated chest with ice. Samples <br /> remain chilled prior to and during transport to a state-certified laboratory for analysis. Sample i <br /> container descriptions and requested analyses are entered onto a chain-of-custody form in order ? <br /> to provide instructions to the laboratory. The chain-of-custody form accompanies the samples <br /> during transportation to provide a continuous record of possession from the field to the <br /> laboratory. If a freight or overnight carrier transports the samples, the carrier is noted on the j <br /> form. <br /> For wells that have been purged using low flow methods, sample containers are filled from the <br /> effluent stream of the bladder or peristaltic pump. In some cases, if so specified by the TSR, <br /> E[r samples are taken from the sample ports of actively pumping remediation wells. <br /> l Sequence of Gauging, Purging, and Sampling <br /> The sequence in which monitoring activities are conducted are specified on the TSR. In <br /> general, wells are gauged beginning with the least affected well and ending with the well that <br /> has highest concentration based on previous analytic results. After all gauging for the site is <br /> completed, wells are purged and/or sampled from the least-affected well to the most-affected <br /> well. <br /> F� <br /> Decontaminations, <br /> if <br /> In order to reduce the possibility of cross contamination between wells, strict isolation and i? <br /> decontamination procedures are observed. Portable pumps are not used in wells with LPH. i! <br /> Technicians wear nitrile gloves during all gauging, purging and sampling activities. Gloves are <br /> changed between wells and more often if warranted. Any equipment that could come in contact <br /> with fluids are either dedicated to a particular well, decontaminated prior to each use, or <br /> discarded after a single use. Decontamination consists of washing in a solution of Liqui-nox <br /> and water and rinsing twice. The final rinse is in deionized water. ' <br /> �3 <br /> Exceptions <br /> a <br /> Additional tasks or non-standard procedures, if any, that may be requested or required for a F <br /> particular site, and noted on the site TSR, are documented in field notes on the following pages. <br /> E <br /> 115104 version <br /> �f <br /> f <br />