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• <br />ATTACHMENT B <br />FIELD AND LABORATORY PROCEDURES <br />Sampling Procedures <br />The sampling procedure for each well consists of measuring the water level and checking for the <br />presence of separate -phase hydrocarbons (SPH), using either an electronic indicator and a clear <br />Teflon® bailer or an oil -water interface probe. Wells not containing SPH are then purged of <br />approximately three casing volumes of water (or to dryness) using a clean centrifugal pump, gas <br />displacement pump, or bailer. The equipment and purging method used for the current sampling <br />event are 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 <br />collecting samples. After purging, water levels are allowed to partially recover. Groundwater <br />samples are collected using either a clean Teflon bailer or a dedicated submersible pump, placed <br />into appropriate EPA -approved containers, labeled, logged onto chain -of -custody documents, and <br />transported on ice to a California State -certified laboratory. <br />Laboratory Procedures <br />Groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg), <br />benzene, toluene, ethyl -benzene, xylenes (BTEX compounds) and fuel oxygenates methyl - <br />tertiary -butyl -ether (MtBE), ethyl -tertiary -butyl -ether (EtBE), di -isopropyl ether (RIPE), tertiary - <br />amyl -methyl -ether (TAME), tertiary -butyl -alcohol (TBA), 1,2-dichloroethane (1,2 -DCA), and <br />ethylene dibromide (EDB), methanol, and ethanol by EPA Method 8260. The methods of <br />analysis for the groundwater samples are documented in the laboratory analytical report. The <br />laboratory analytical report and chain -of -custody documentation are presented as Attachment B. <br />Purge and Rinsate Water Disposal <br />Water generated during well sampling and equipment cleaning was pumped into a SECOR truck <br />mounted water tank. The water was then transferred to the operating GWE system where it was <br />treated and then discharged under permit to the industrial wastewater stream. <br />• <br />