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'STANDARD OPERATING PROCEDURE - e <br /> GROUNDWATER SAMPLING ",,j; <br /> Gettler-Ryan Inc Field personnel adhere to the following procedures for the collection and handling <br /> of groundwater samples prior to analysis by the analytical laboratory Prior to sample collection, the <br /> type of analysis to be performed is determined Loss prevention of volatile compounds is controlled <br /> and sample preservation for subsequent analysis is,maintained <br /> 2 <br /> I ,- . <br /> Prior to sampling, the presence or absence of free-phase hydrocarbons is determined using a MMC <br /> flexi-dip interface probe Product thickness, if present, is measured to the nearest 0 01 foot and is <br /> noted in the field notes In addition, static water level measurements are collected with the interface <br /> probe and are also recorded in the field notes, " <br /> z <br /> After water levels are collected and prior to sampling, each well is purged a minimum of three well <br /> casing volumes of water using pre-cleaned pumps (stack, suction, Grundfos), or polyvinyl chloride <br /> bailers Temperature, pH and electrical conductivity are measured a minimum of three times during <br /> the purging Purging continues until these parameters stabilize` <br /> Groundwater samples are collected using disposable bailers The water samples are transferred from <br /> the bailer into appropriate containers Pre-preserved containers, supplied by analytical laboratories, . <br /> are used when possible When pre-preserved containers are not available, the laboratory is instructed <br /> to preserve the sample as appropriate Duplicate samples are collected for the laboratory to use in <br /> _maintaining quality assurance/quality control standards ,, The samples are labeled to include the,lob <br /> number, sample identification, collectiond`ate and tune;analysis;preservation(if any),=and the sample= <br />--- <br /> collector!s_initials The water—samples-are placed. in.a cooler, maintained at 4oC for transport to the <br /> laboratory Once collected in the field, all samples are maintained under chiin ofcustody unttl �"� T <br /> The chain of custody document includes the job number, type of preservation, if any, analysis <br /> requested, sample identification, date and time collected, and the sample collector's name The chain <br /> of custody is signed and dated (including time of transfer) by each person who receives or surrenders <br /> the samples, beginning with the field personnel and ending'with the laboratory personnel <br /> A laboratory supplied trip blank accompanies each sampling set For sampling sets greater than 20 <br /> samples, 5% trip blanks are included The trip blank is analyzed for some or all of the same <br /> compounds as the groundwater samples <br /> As requested by Unocal Corporation, the purge water and decontamination water generated during <br /> sampling activities is transported to Tosco' - San Francisco Area Refinery, located in Rodeo, <br /> California <br /> Mformslunocalsop frm-1198 <br />