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Groundwater Elevation Data Depth to groundwater was obtained from the existing groundwater monitor wells at the site using a water level indicator graduated to 0 01 foot The depth to groundwater measurement was converted to a groundwater elevation for each well and used to construct a groundwater elevation contour map (Figure 2), and calculate the local groundwater flow direction and hydraulic gradient Groundwater at the site was measured at depths between 70 23 to 84 67 feet below ground surface (bgs) The groundwater potentiometric surface elevation averaged approximately 24 20 feet bgs during this monitoring event The groundwater elevation has increased approximately 0 03 feet since the last sampling event in November 2001 The groundwater flow direction during this reporting period is toward the southwest with a hydraulic gradient of approximately 0 02 ft/ft A summary of data regarding groundwater levels measured through March 4, 2002 is presented in Table 1 Copies of field observations documenting work performed at the site are presented in Attachment I Groundwater Analytical Results The distribution of groundwater sample analytical results obtained from monitor wells at the site on March 4, 2002, is presented on Figure 3 and summarized in Table 2 The highest concentration of petroleum hydrocarbons is in the vicinity of monitor well MW-1 TPHg and benzene concentrations were below method detection limits for all wells sampled during this monitoring event except MW- 1 MTBE was below detection limits in all wells except MW-4 and MW-5 at 0 7 and 0 5 micrograms per litter (ug/L) respectively Attachment II contains photocopies of the laboratory analytical report and the chain-of-custody form On March 4,2002,LPH was not detected in MW-1 during this monitoring event and therefore was sampled LPH continues to be monitored and removed (if necessary) from MW-1 by hand bailing methods and the use of a passive, down-hole petroleum skimmer on a weekly basis A total of approximately 62 gallons of LPH has been removed from MW-1 since its detection in February 2000 Purge Water Purge water generated during groundwater purging is currently contained on-site in Department of Transportation rated 55-gallon drums and will be removed to a disposal/recycling facility during June 2002 SITE REMEDIATION Construction of a soil and groundwater remediation system was completed at the site in December 1999 The remediation system consists of seven soil vapor extraction (SVE) wells (W-1, W-3 through W-8), two groundwater monitor wells modified for SVE (MW-1 and MW-3) and four air sparge wells (AS-1 through AS-4) with catalytic oxidation treatment A Site Plan depicting the locations of the remediation wells, subsurface piping, and remediation equipment compound is included as Figure 4 Initial start-up air discharge compliance testing was completed on December 13, 1999 The San Joaquin County Valley Air Pollution Control District(SJVAPCD)has approved C 1Tima 0ffU.0&*fordQ102 2 SECOR 770T 41737 00 003