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canister. <br /> The sample tubing and sampling apparatus shall be purged of at least one purge volume prior to <br /> sample collection. The flow rate during sample purging shall be maintained between 100 and 200 <br /> milliliters per minute, and the flow rate shall be measured and recorded. Photoionization detector <br /> (PID) measurements of the soil vapor will be collected from the boring immediately following the <br /> removal of the first purge volume. PID measurements will continue to be collected until the <br /> concentration of VOCs measured in the purged vapor stabilizes or a maximum of three purge volumes <br /> is reached. <br /> A soil gas sample will be collected using the flow regulator attached to the Summa canister,a process <br /> that should take approximately 6 to 10 minutes. To check for system leaks, a swab containing <br /> isopropyl alcohol will be placed in the vicinity of the borehole seal and the connection between the <br /> plastic tubing from the probe and the Summa canister regulator for approximately one minute during <br /> sample collection. The VOC applied to the swab,2-propanol, is not a constituent associated with the <br /> past LNC site releases and provides a means of leak detection. <br /> Once the soil gas sample has been collected the sampling rod will be withdrawn and the hollow stem <br /> augers will be backed out for five feet to allow the bentonite slurry seal to be punched out of the <br /> augers. Once drilling is resumed soil samples will be collected until the next interval where soil gas <br /> is to be collected is reached. The soil gas sample will then be collected as outlined above. <br /> Soil gas samples shall be transported to the laboratory under chain-of-custody procedures using the <br /> containers supplied by the laboratory or in clean plastic coolers with packing materials. Ice cooling <br /> is not required, and sample holding time is 30 days. <br /> Quality control samples shall include one ambient airsample per day and one duplicate sample. One <br /> trip blank shall be included with each batch of samples sent to the laboratory. Trip blanks are to be <br /> submitted to the laboratory on hold pending the results of the accompanying samples. <br /> Environmental/LNC/Workplan/Appendix 2.wpd 5 <br />