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cooled ice chest for later shipment to the laboratory All five samples were analyzed foi TPH-diesel . The laboratory report is contained in Appendix B 3 0 RESULTS 31 Depth to Groundwater and Hydraulic Gradient Table 1 provides all depth-to-groundwater measurements and calculated groundwater elevations The depth in all wells was slight greater than 67 feet on July 27 This is an increase of almost 3 feet since December 2003 The calculated water table elevations were used to construct the groundwater elevation map in Figure 3 Elevation contours again form an are that is centered in the southern part of the site The water level is higher to the east, north, and west of GT-1, implying that the groundwater flow direction is to the south, as indicated by the arrow in the figure The new casing elevation of GT-9 has not been surveyed, so this well was not used in construction of the map The casing will be surveyed in conjunction with the-installation of the next set of monitoring wells later this year 3.2 Analytical Results The laboratory results are shown in Table 2 Diesel-range hydrocarbons were again detected in monitor wells GT-1, GT-6, and GT-9, at concentrations that are consistent with those previously detected in these wells The laboratory report described the chromatograms as being representative of "aged" (degraded) diesel fuel All three of these wells lie generally south of the former UST facility, in the direction of recent groundwater flow Well GT-3 remained free of contaminants, despite its location near the UST facility 4 0 SUMMARY The depth to groundwater has increased by approximately 3 feet since December of 2003, but the flow direction remains southward Diesel-range hydrocarbons were detected in thiee of five monitor wells, at concentrations ranging between 100 and 700 parts per billion The sample chromatograms are characteristic of old, partially oxidized fuel that has lost some of the lighter components due to weathering San Joaquin County EHD has requested additional investigation to determine the extent and vertical-distribution ofgroundwater contamination iat the site, and a work plan to address that issue has been prepared As many as 18 additional wells, independently screened in separate aquifers, have been proposed to complete the assessment Quarterly groundwater monitoring will continue as new wells are added to the monitoring program 2