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ATTACHMENT B <br /> FIELD AND LABORATORY PROCEDURES FOR GROUNDWATER SAMPLING <br /> ' <br /> Sampling Procedures <br /> P g <br /> ' Sampling equipment is thoroughly cleaned prior to use in each well. The sampling procedure for each <br /> well consists first of measuring the water level and checking for the presence of separate-phase <br /> hydrocarbons (SPH), using either an electronic indicator and a clear Teflon® bailer or an oil-water <br /> interface probe. Wells not containing SPH that do not have submerged screens are then sampled without <br /> purging. Wells that have submerged screens are purged of approximately three casing volumes of water <br /> (or to dryness) using a centrifugal pump, gas displacement pump, or bailer. The equipment and purging <br /> ' method used for the current sampling event is noted on the attached field data sheets. During purging, <br /> temperature,pH, and electrical conductivity are monitored in order to document that these parameters are <br /> stable prior to collecting samples. After purging, water levels are allowed to partially recover. <br /> Groundwater samples (both purge and no-purge) are collected using a Teflon® bailer, placed into <br /> appropriate EPA-approved containers, labeled, logged onto chain-of-custody documents, and transported <br /> on ice to a California state-certified laboratory. <br /> Laboratory Procedures <br /> ' The groundwater samples are analyzed for the presence of TPHg, benzene, toluene, ethylbenzene, and <br /> xylenes (total) using EPA Methods 8015 (modified) and 8020, and fuel oxygenates and volatile organic <br /> compounds (VOCs) using EPA Method 8260B. The methods of analysis for the groundwater samples <br /> ' are documented in the laboratory analytical report. The laboratory analytical report, chain-of-custody <br /> documentation,and field data sheets are presented as appendices. <br /> Purge and Rinsate Water Disposal <br /> Water generated during well sampling and equipment cleaning is pumped into a truck-mounted water <br /> tank. The water is transported to the Blain Tech holding facility in Roseville, California, for temporary <br /> storage. The water is then transported by Dillard Environmental Services to Altamont Landfill and <br /> Disposal Facility in Altamont,California for disposal. <br /> ' 9200711A/SITEPULL.DOC A-2 October 28,2002 <br />