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t <br /> ZO Quarterly Activities <br /> 1 <br /> Quarterly monitoring activities were conducted on August 22, 1996 The groundwater depth in <br /> each monitoring well was measured using a Solinst water level meter. A summary of the <br /> measured groundwater depths is presented in Table 1. <br /> Approximately three well volumes of groundwater were purged from each monitoring well <br /> using a decontaminated submersible pump Groundwater parameters including pH, electrical <br /> conductivity, dissolved oxygen and temperature were monitored during purging. After purging <br /> the wells, or when groundwater parameters stabilized, groundwater samples were collected in <br /> ' one liter glass amber bottles One quality control sample (equipment nnsate) was also collected <br /> prior to the commencement of sampling Each sample was labeled, sealed and packed in an ice- <br /> box cooler that was maintained at a temperature of approximately 4'C using water-ice. The <br /> sample coolers were delivered to McCampbell Analytical Inc (DHS Certification No. 1644), <br /> located in Pacheco, California, for sample analysis. Groundwater sampling forms containing the <br /> data collected are presented in Appendix A. <br /> The groundwater samples were analyzed for total petroleum hydrocarbons (TPH) as diesel only <br /> With the concurrence of the San Joaquin County Senior Registered Environmental Health <br /> ' Specialist, groundwater analysis for TPH as gasoline and BTEX has been suspended since <br /> November 1995. This is because TPH as gasoline and BTEX are apparently absent from the <br /> site. <br /> The samples collected during this sampling event were analyzed for TPH as diesel using <br /> ' modified EPA method 8015 A summary of the groundwater analytical results for the site is <br /> presented in Table 2 Analysis Request and Chain-of-Custody (ARCC) records accompanied the <br /> samples at all times (Appendix B). The Certified laboratory report, which includes the results <br /> for all the samples that were analyzed, is presented in Appendix C. <br /> ' detection limits followed those defined in the Regional Water Quality Control Board's <br /> Method de gi Qu ty <br /> Tri Regional Board Staff Recom mendations for Preliminary Evaluation and Investigation of <br /> Underground Tank Sites, dated August 1990. <br /> N 09-18-96/VDBF/96-0019 js 2-1 <br />