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ATTACHMENT A <br /> FIELD AND LABORATORY PROCEDURES <br /> Sampling Procedures <br /> The sampling procedure for each well consists first of measuring the water level and checking for the presence <br /> of separate-phase hydrocarbons (SPH), using either an electronic indicator and a clear Teflon® bailer or an <br /> oil-water interface probe. Wells not containing SPH that do not have submerged screens are then sampled <br /> without purging. Wells that have submerged screens are purged of approximately three casing volumes of <br /> water (or to dryness) using a centrifugal pump, gas displacement pump, or bailer. 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. Groundwater <br /> samples (both purge and no purge) arc collected using a Teflon bailer, placed into appropriate EPA-approved <br /> containers, labeled, logged onto chain-of-custody documents, and transported on ice to a California State- <br /> 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, xylenes, and methyl tertiary butyl ether by EPA Methods 8015 <br /> (modified), 8020. and 5030. VOCs and fuel oxygenates were analyzed for by EPA Method '9260. The <br /> methods of analysis for the groundwater samples are documented in the certified analytical report. The <br /> certified analytical report, chain-of-custody documentation, and field data sheets are presented as Attach- <br /> ment B. <br /> i <br />