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1 � <br /> t <br /> May 18 , 1992 ?4 <br /> E <br /> 19060, 025 . 03 M AY 2 a 1992 Harding Lawson Associates <br /> Mr. Bud Good <br /> The Southland Corporation ENVIROM\'ENTAL HEALTH <br /> ' Page 2 PERM IT/SERVIGES <br /> GROUNDWATER SAMPLING <br /> On March 31, 1992 , HLA collected groundwater samples from all 14 <br /> monitoring wells. Before sampling, we purged at least three <br /> € casing volumes from each well while monitoring temperature, pH, <br /> and conductivity. After those parameters stabilized, <br /> groundwater samples were collected with a clean stainless steel <br /> S bailer, and decanted directly into laboratory-prepared volatile <br /> organic analysis (VOA) vials and sterilized fecal coliform <br /> sample containers. The samples were labeled and placed into an <br /> ice-chilled cooler for transportation, under chain-of-custody, <br /> to a state-certified chemical testing laboratory. Between <br /> wells, all purging and sampling equipment was cleaned with an <br /> Alconox solution and rinsed with deionized water. A duplicate <br /> sample and a laboratory-provided trip blank were analyzed to <br /> provide quality control. <br /> CHEMICAL TESTING <br /> Samples were sent to Superior Analytical Laboratories in <br /> Martinez, California, and analyzed for total petroleum <br /> hydrocarbons (TPH) as gasoline, using EPA Test Method 8015 ; and <br /> for benzene, toluene, ethylbenzene, and xylenes (BTEX) , using <br /> EPA Test Method 8020. Samples for fecal coliform were submitted <br /> to BC Analytical in Emeryville, California. The results of <br /> chemical analyses are presented in Table 1, along with <br /> groundwater data from preceding phases of site investigation and <br /> characterization. Laboratory data sheets and chain of custody <br /> are included in the Appendix. <br /> QUALITY ASSURANCE/QUALITY CONTROL (QA/QC) <br /> The results of analyses on QA/QC water samples collected on <br /> March 311 1992 are presented in Table 1. A duplicate <br /> groundwater sample from MW-9 was analyzed during this quarter. <br /> This sample is identified as MW-16 in the attached laboratory <br /> report. Analyses of the duplicate sample detected similar <br /> concentrations for all analyses. The results from the <br /> laboratory-provided trip blank (MW--17) indicated non-detectable <br /> concentrations for all compounds tested. <br /> { GROUNDWATER GRADIENT <br /> C' <br /> Water level measurements were obtained using a chalked steel <br /> tape accurate to 0. 01 feet. Well survey and water level data <br /> are presented in Table 2 . The water levels in each of the wells <br /> i <br /> r <br />