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i <br />-' -� GROUNDWATER MONITORING REPORT <br /> USA PETROLEUM - STOCKTON #110 <br /> JANUARY, 1995 <br /> 2.0 GROUNDWATER MONITORING WELL SAMPLING METHODOLOGY <br /> ' 2.1 Groundwater Elevations <br /> ' Depth to groundwater measurements were collected on December 8, 1994 using an electronic <br /> water level indicator The depths were measured from the top of the surveyed well casings <br /> ' Groundwater measurements collected during this and previous events are presented in Table I <br /> 2.2 Monitoring Well Purging <br /> Each monitoring well was purged by hand-bailing with a new disposable Teflon bailer, until <br /> the equivalent of at least three well volumes of water had been removed As groundwater was <br /> removed from the wells, pH, temperature and conductivity were monitored and recorded on <br /> field data sheets, which are maintained in our office The wells were allowed to stand for a <br /> ' period of time to regain equilibrium prior to sampling Groundwater purged from the wells <br /> was placed in DOT approved 55-gallon drums The contents will be disposed of using proper <br /> methods and protocol after analytical results review A summary of field data is presented in <br /> Table II, and copies of the field data sheets are included in Appendix C <br /> ' 2.3 Groundwater Sampling <br /> Each groundwater sample was collected using a new Teflon disposable bailer The sampled <br /> ' water was placed in laboratory prepared sterile 40 milliliter glass, one liter plastic, and one <br /> quart amber containers The sample containers were filled to the top to expel air space and <br /> were scaled with Teflon-lined caps Water sample containers were labeled with the name of <br /> ' the sampler, the date, the,lob number, the preservative, and an identifying number 'The <br /> samples were then transported to Sierra Laboratories (Sierra), in Anaheim, California a state <br /> ' certified laboratory Full sham-of-custody protocol was followed during sample handling and <br /> delivery <br /> 2.4 Groundwater Analyses <br /> ' Analyses of the groundwater samples were performed by Sierra in accordance with state <br /> guidelines and EPA protocol The samples were analyzed for TPH G, TPH D, BTEX, and <br /> total lead using EPA methods 8015, 8020 and 7421, respectively <br /> 5007 B 2 <br />