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S E C ® R I • Mr Scott Sloan May '17, 2004 Page 2 groundwater elevation contour map, the local groundwater flow direction and hydraulic gradient were evaluated Groundwater at the site was measured at depths between 71 68 to 93 16 feet below ground surface(bgs) The groundwater potenhometric surface elevation averaged approximately 23 88 feet above mean sea level during this monitoring event The groundwater elevation Increased an average of approximately 0 39 feet since the last sampling event in October 2003 The groundwater flow direction during this reporting period was predominantly toward the south/southwest with a hydraulic gradient of 0 06 feet per foot(ft/ft) A summary of groundwater level data measured through January 5, 2004 is presented in Table 1 Copies of field observations documenting work performed at the site are presented in Attachment 1 GROUNDWATER ANALYTICAL RESULTS The distribution of groundwater sample analytical results obtained from monitor wells at the site on January5, 2004 is presented on Figure 3, and summarized in Tables 2 and 3 With the exception of a concentration of MTBE reported in MW-9 at 2 4 micrograms per liter(ug/L),TPHg, BTEX,and fuel oxygenates were reported below laboratory method detection limits in all wells sampled Attachment 2 contains photocopies of the laboratory analytical report and chain-of-custody documentation LPH is monitored and removed(if necessary)from MWA by hand bailing methods and the use of a passive, down-hole petroleum skimmer LPN was reported in the well for the second consecutive quarter at a thickness of 0 02 feet Until October 2003, LPH had not been present in the well since July 2002 LPH was not removed from MW-1 this quarter,due to the small quantity in the well A total of approximately 62 gallons of LPH have 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 pending removal to a disposal/recycling facility SITE REMEDIATION Construction of a sod and groundwater remediation system was completed at the site in December 1999 The remediation system consists of seven SVE wells (W-1, W-3 through W-8), two groundwater monitor wells modified for SVE(MW-1 and MW-3), and four AS 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)approved an air permit for the site Since the SVE/AS system began operation in December 1999, a total of approximately 38,894 pounds of gasoline and 233 2 pounds of benzene have been removed and treated at the site On September 16, 2003,the SVE/AS system was shut down following the receipt of verbal authorization from the San Joaquin County Public Health Department(SJCPHD)and has remained off-line through the first quarter 2004 The SJCPHD approved the non-operation of the system as a result of low soil vapor influent concentrations 1\Time Od\Lockeford\QMRs\2001-2004\Lockeford 01-04 doc SECOR Intemational Incorporated