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June 1999, and diesel-range hydrocarbons and benzene, toluene, MTBE, and TAME were <br /> reported by the laboratory in well TT-2 In the following quarter, diesel was detected in TT-2 but <br /> no other hydrocarbons were present After reviewing the results, Ms Oz requested that sampling <br /> of TT-2 be continued for one additional quarter She also requested that we contact the owners of <br /> the well at 705 Lodi Ave and obtain information about the well, and that we review the <br /> PHS/EHD microfiche file on other wells in the area The results of these activities are discussed <br /> in this report <br /> 3.0 PROCEDURES <br /> Monitoring was performed on December 21, 1999 Upon arrival at the site, the wells were opened <br /> and allowed to equalize with atmospheric pressure A Solinst water level meter was used to <br /> measure the depth to groundwater in the monitoring wells Depth measurements were recorded on <br /> the Well Monitor Report (Appendix A) and are shown in Table 1 After water depths were <br /> measured, a Grundfos Redi-flow 2 submersible pump was lowered into TT-2 and approximately 20 <br /> gallons of water were pumped out Temperature and other parameters were not measured, and <br /> neither of the other wells was purged <br /> After purging, a new disposable bailer was used to collect a sample from TT-2 A 1-liter amber <br /> bottle was filled and placed in a cooled ice chest, and transported to Sequoia Analytical for analysis <br /> 01 The laboratory report is included in Appendix B <br /> 4.0 RESULTS <br /> 4.1 Depth to Groundwater <br /> Currently, the depth averages 52 feet below grade This represents a one-foot rise in the static <br /> water level since August (Table 1) <br /> 4.2 Groundwater Gradient <br /> Figure 3 illustrates the present hydraulic gradient and direction of groundwater flow, and <br /> includes a rose diagram (lower right corner) that summarizes flow directions measured in <br /> previous monitoring events In general, the direction of flow has been to the south The present <br /> gradient is estimated to be 0 005 ft/ft, in August, the gradient was nearly identical (0 0055 ft/ft) <br /> 4.3 Analytical Results <br /> Diesel was not detected this quarter (Table 2 and Appendix B) In the previous two quarters, <br /> diesel had been detected at 1 and 30 parts per billion (ppb)above the laboratory's reporting limit <br /> These numbers represent very small concentrations, and in view of the fact that TT-2 is located <br />., 2 <br />