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well, the WEGE geotechnician measured the depth to ground water <br /> using a resistance probe. A ground water contour surface was <br /> later plotted from these depth-to-water measurements; ground <br /> water flow directions at the site were then inferred from the <br /> contour gradients . This information is presented in Figure 4D. <br /> Each well was purged before collecting water samples . Purging <br /> was completed only after water temperature, pH, and conductivity <br /> had stabilized. Purged water was contained in a labeled, secured <br /> 55 gallon drum on site . <br /> The wells were allowed to recover after purging. A water sample <br /> was then collected with a fresh bailer. Each sample was divided <br /> among two 40-m1 VOA vials . The vials are supplied pre-cleaned to <br /> exact EPA protocols and contain the appropriate preservative. <br /> The sample vials were labeled as to station, well, time, and <br /> sampler, and documented on the chain-of-custody sheet; they were <br /> then placed into an ice chest and cooled to 40C with ice . The <br /> samples were delivered to a California State Certified <br /> Laboratory and signed over to the lab using standard chain-of- <br /> custody procedures . Field notes describing the collection of <br /> water samples are included in Appendix A. <br /> Chemical Analysis Results <br /> The water samples were analyzed at American Environmental <br /> Network, AEN (DHS #1172) for Total Fuel Hydrocarbons (gasoline) <br /> with BTEX distinction, utilizing EPA Methods 5030 and 602, <br /> respectively. The analytical results from the water samples (MW1, <br /> MW2, MW3 , MW5, MW6 and MW7) were all Below Reportable Limits <br /> (BRL) . MW4 and MW8 indicated a level of TFH of 0 . 3 mg/L, and 7 <br /> mg/L respectively. Benzene concentrations are 8 and 500 µg/L for <br /> MW4 and MW8 respectively. <br /> The current localized impact of TFH-gasoline and benzene on <br /> ground water is depicted in Figures 5D and 6D. The analytical <br /> results and pertinent reference data are listed in Table 1 . <br /> Anlab' s laboratory report is included as Appendix B . <br /> DISCUSSION OF RESULTS <br /> The ground water data obtained during the current monitoring <br /> round show significant changes since the last quarterly <br /> monitoring report . Ground water flow direction is to the south- <br /> southwest from MW1 to MW7 with an average gradient of 0 . 003 feet <br /> per linear foot . <br /> 4 USA 65 Mar. ' 95 Qtr Rpt <br />