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4.0 RESULTS 4.1 Depth to Groundwater and Hydraulic Gradient The depth to groundwater on June 14 was between 35 and 36 feet, which is two feet less than the depth in January 2005 (Table 1) The calculated elevation of the water table is approximately 20 feet below sea level Figure 3 illustrates the hydraulic gradient and general direction of groundwater flow As in previous quarters, the contours indicate that the piezometric surface slopes eastward and is steeper beneath Grant Street (west of the site)than beneath the site itself 4.2 Analytical Results Hydrocarbon concentrations in June were somewhat lower than those measured in January in most wells (Table 2) In VM-1, the TPH-g concentration was roughly 54% of the January concentration In VM-4, VM-6, and VM-7, this concentration declined by more than 50% In VM-2, all analytes were detected at approximately 80% of their January concentrations 5.0 REMEDIATION ACTIVITIES A vapor extraction line was installed near the end of the first quarter of 2005 A concrete saw was used to remove the concrete and dig a 1-foot wide trench from the vapor extraction unit to the extraction well (VT-1) Schedule 40 PVC pipe was lard in the trench and temporarily covered with gravel The trench will be paved over with corierete alter the vapor extraction system has been tested and inspected by the San Joaquin Valley Air Pollution Control District The only other remedial activity that was performed since the First Quarter 2005 Report was prepared was the submission of an application to install a temporary propane gas tank at the site to supply supplemental fuel to the vapor extraction unit The application was prepared in late April-early May, but the tank has not yet been mobilized � I • 3