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STANDARD OPERATING PROCEDURE- <br /> GROUNDWATER SAMPLING <br /> Gettler-Ryan Inc field personnel adhere to the following procedures for the collection and handling of <br /> groundwater samples prior to analysts by the analytical laboratory Prior to sample collection, the type <br /> of analysis to be performed is determined. Loss prevention of volatile compounds is controlled and <br /> sample preservation for subsequent analysis is maintained <br /> Prior to sampling, the presence or absence of free-phase hydrocarbons is determined using an interface <br /> probe. Product thickness,if present, is measured to the nearest 0.01 foot and is noted in the field notes <br /> In addition,static water level measurements are collected with the interface probe and are also recorded <br /> in the field notes <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 the <br /> purging Purging continues until these parameters stabilize <br /> Groundwater samples are collected using Chevron-designated disposable bailers. The water samples are <br /> transferred from the bailer into appropriate containers. Pre-preserved containers, supplied by analytical <br /> laboratories, are used for all samples 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,collection date and time, analysis, preservation (if any), and the sample <br /> collector's initials. The water samples are placed in a cooler, maintained at 40C for transport to the <br /> laboratory. Once collected in the field,all samples are maintained under chain of custody until delivered <br /> to the laboratory <br /> The chain of custody document includes the fob number,type of preservation,if any,analysis requested, <br /> sample identification,date and time collected, and the sample collectors name. The chain of custody is <br /> signed and dated (including time of transfer) by each person who receives or surrenders the samples, <br /> 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 compounds <br /> as the groundwater samples. <br /> As requested by Chevron Products Company, the purge water and decontamination water generated <br /> during sampling activities is transported by IWM to McKittnck Waste Management located in <br /> McKittrick, California <br /> N;Ca1sfa=Vo n s%Awv xi-SOP 1QW <br />