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• • Chevron Products Company Page 1 Former Chevron Service Station #9-5775, 301 West Kettleman Lane, Lodi, California October 31, 2002 1.0 INTRODUCTION SECOR International Incorporated (SECOR), on behalf of Chevron Environmental Management Company (CEMC), presents third quarter 2002 QQ02) groundwater monitoring and sampling results, and operational data for the groundwater extraction (GWE) and soil vapor extraction (SVE) systems at 301 West Kettleman Lane, Lodi, California (Figure 1). This report was prepared in accordance with Cleanup and Abatement Order (CAO) No. 5-00- 704, dated April 20, 2000 (Attachment A). 2.0 GROUNDWATER MONITORING AND SAMPLING Between July 29 and 30, 2002, Gettler-Ryan conducted 3Q02 groundwater monitoring and sampling. Wells were gauged on July 29, 2002, and sampled on July 29 and 30, 2002. Field and laboratory procedures are presented in Attachment B. Certified laboratory analytical reports and chain -of -custody documentation and monitoring and sampling field data sheets are included in Attachments C and D, respectively. A brief description is presented below. 2.2 Monitoring Well Gauge Data During the 3Q02, monitoring well gauge data indicates the approximate depth to groundwater in A, B, and C -zones ranges from 59.10 to 68.45 feet below ground surface (bgs). Gauge data is presented as Table 1. Groundwater in the A -zone near the site appears to flow radially toward extraction well EX -3 (Figure 2). Groundwater in the B -zone flows to the south to southeast, with an approximate hydraulic gradient of 0.003 feet/feet (ft/ft) to 0.016 ft/ft (Figure 3). 2.1 Sample Analytical Results During the 3Q02 event groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethyl -benzene, and total xylenes (BTEX), methyl tertiary butyl ether (MtBE), tertiary butyl alcohol (TBA), di -isopropyl ether (RIPE), ethyl tertiary butyl ether (ELBE), tertiary amyl methyl ether (TAME), ethanol, methanol, ethylene di -bromide (EDB), and 1,2-dicholoethane (1,2 -DCA). Sample analytical results are presented as Table 2. Maximum concentrations of detected constituents for A, B, and C - zones are presented in the table below. An A -zone isoconcentration contour map for MtBE is presented as Figure 4. I:1Chevron1957751Periodic Monitoring\Quarterly Progress Reports1200213rd Quarter -2002 Progress Report.doc