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ATTACHMENT A <br /> FIELD AND LABORATORY PROCEDURES <br /> Sampling Procedures <br /> Sampling equipment is thoroughly cleaned prior to use in each well The sampling procedure for each well <br /> consists first of measuring the water level and checking for the presence of separate-phase hydrocarbons(SPH), <br /> using either an electronic indicator and a clear Teflon® bailer or an oil-water interface probe Wells not <br /> containing SPH that do not have submerged screens are then sampled without purging Wells that have <br /> submerged screens are purged of approximately three casing volumes of water (or to dryness) using a <br /> centrifugal pump, gas displacement pump, or bailer The equipment and purging method used for the current <br /> sampling event is noted on the attached field data sheets During purging, temperature, pH, and electrical <br /> conductivity are monitored in order to document that these parameters are stable prior to collecting samples <br /> After purging, water levels are allowed to partially recover Groundwater samples (both purge and no purge) <br /> are collected using a Teflon bailer, placed into appropriate EPA-approved containers, labeled, logged onto <br /> cham-of-custody documents,and transported on ice to a California State-certified laboratory <br /> Laboratory Procedures <br /> The groundwater samples were analyzed for the presence of total petroleum hydrocarbons calculated as <br /> gasoline,benzene, toluene,ethylbenzene, and xylenes by EPA Methods 8015 (modified) and 8020 VOCs and <br /> fuel oxygenates were analyzed for by EPA Method 8260 The methods of analysis for the groundwater <br /> samples are documented in the certified analytical report The certified analytical report, chain-of-custody <br /> documentation,and field data sheets are presented as Attachment B <br /> Purge and Rinsate Wafer Disposal <br /> Water generated during well sampling and equipment cleaning is pumped into a SECOR truck mounted water <br /> tank The water is transported to ARCO's holding facility in West Sacramento, California, for temporary <br /> storage Water is then transported by Integrated Waste Management (IWM) to Seaport Environmental in <br /> Redwood City,California for disposal <br />