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If PSH thickness is less than 0.02 foot,and the well is planned for purging prior to <br /> sample collection, the well is purged and sampled in accordance with the sample collection <br /> section of this SOP If the PSH thickness is 0.02 foot or greater, the PSH is bailed from the well, <br /> and left onsite in a labeled and sealed container.No sample is collected for analysis from wells <br /> having a PSH thickness of greater than 0 02 foot <br /> 4. No-Purge Sampling <br /> Well purging is not conducted prior to sampling if purging is not needed to meet <br /> technical and/or <br /> regulatory project requirements Following collection of water level measurements,wells <br /> that are not purged are sampled according to the protocol in the sample collection section of this <br /> SOP <br /> 5. Purging Procedures <br /> Well purging is conducted prior to sampling if purging is needed to meet technical and/or <br /> regulatory project requirements If purging is conducted, the monitoring wells are purged using a <br /> vacuum truck, submersible electric pump, bailer, hand pump, or bladder pump, as appropriate for <br /> site conditions A surge block may be used if it becomes apparent during purging that the well <br /> screen has become bridged with sediment or the produced groundwater is overly turbid <br /> During the purging process, groundwater is monitored for temperature, pH,conductivity, <br /> turbidity, odor, and color These parameters are recorded on a water sample log. Purging <br /> continues until all stagnant, water within the wells is replaced by fresh formation water, as <br /> • indicated by removal of a minimum number I of well volumes and/or stabilization of the <br /> above-outlined parameters Sampling is performed after the well recharges to at least 80 percent <br /> of hydrostatic <br /> Purge water is stored on site in Department of Transportation-approved, 55-gallon drums <br /> until water sample analytical results are received from the laboratory If active groundwater <br /> treatment is occurring at the site, purge water may be disposed of through the treatment system, <br /> or the purge water may be transported offsite as non-hazardous waste to an approved off-site <br /> disposal facility If permanent pumps are installed in the wells for groundwater remediation, <br /> purging may be accomplished by operating the pumps for at least 24 hours before sampling to <br /> ensure adequate purging <br /> Ile <br /> I <br />