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One vapor extraction well will be installed in the 20-foot boring The vapor extraction well will <br /> • be constructed in a similar fashion to the described groundwater monitoring wells except it will <br /> not be constructed below static groundwater level The screened interval would be chosen based <br /> on the depths of any observed soil contaminants, but would likely be placed from 10 to 20 feet <br /> bgs <br /> 3.7 Well Development <br /> Each groundwater monitoring well will be developed using a surge block for at least'30 minutes, <br /> and then purged of at least three well volumes of groundwater During purging, values of pH, <br /> conductivity and temperature will be monitored and recorded The well will be allowed to stand <br /> for a sufficient period of time for the groundwater to equilibrate within 80 percent of static <br /> groundwater level prior to sampling <br /> 3.8 Groundwater Sampling <br /> Groundwater samples will be collected after the well has sufficiently equilibrated to static <br /> groundwater levels In the event that the wells are not sampled within 24 hours of well <br /> development and purging, each well will again be purged with a bladder or submersible pump <br /> until at least three well volumes have been removed Groundwater samples will be collected <br /> using a teflon or new disposable bailer and placed in the appropriate containers in the'appropriate <br /> manner The samples will be placed in a cooler at 4 degrees centigrade or less ands,transported <br /> to a laboratory under proper chain of custody documentation <br /> 39 Groundwater Analyses <br /> Analyses of the groundwater will be performed by a California certified laboratory in accordance <br /> with State guidelines and EPA protocol The groundwater samples will be analyzed for TPH, <br /> BTEX and total lead using EPA methods 8015, 8020, and 7421, respectively In addition to <br /> samples from each well, one equipment blank and one field duplicate will be collected and <br /> analyzed for the same chemical constituents <br /> 3 10 Vapor Treatability Testing <br /> Vapor treatability testing will be performed to assess whether soils contain vapor phase <br /> constituents and to evaluate the site suitability for using vapor extraction as the remediation <br /> technology The testing will consist of applying a vacuum on the well head and measuring flow <br /> and vacuum values for that well, while monitonng nearby wells for vacuum Vapor samples will <br /> be collected for TPH and BTEX analysis using EPA methods 8015 and 8020, respectively <br /> A1125JIWP <br />