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t of the complete Laboratory Certificate of Analysis is enclosed for only this sampling event. On January 28, 2002, ACT Inc. performed a pump test on a 15" extraction well with a 6" PVC casing. The report for this pump test has been supplied as part of a Final Remedial Plan. Gregg Drilling installed CPT#1 to a depth of 90 feet with soil and groundwater sampling to a depth of 78 feet on March 3, 2003. Three samples of soil and three samples of the groundwater were extracted and analyzed. All CPT soil and groundwater samples were analyzed as non-detect. The work plan for installing and operating the "Pump and Treat System" has been approved by the San Joaquin County Environmental Health Department. MONITORING WELL SAMPLE EVENT OF 07/02/03 FINDINGS AND RECOMMENDATIONS Sampling Procedure On July 2, 2003 Del-Tech Geotechnical Services, under the supervision of Foothill Engineering, performed a quarterly groundwater monitoring event. Marcel Delacruz of the Caltrans was notified of the monitoring event on June 25, 2003, as required by Caltrans Permit No.1002-6NV-0218. All monitoring wells were vented and purged by standard of the industry methods(see Groundwater Field Report by Del-Tech Geotechnical Services,attached).Purge rates were 0.5 gal/min.Groundwater samples were extracted from each monitoring well using the Watera Inertia Pump technique with dedicated sample tubes. Samples were transported on ice for delivery under chain of custody to GeoAanalytical Laboratories for analysis. The extraction well,EW-1,was also sampled and that sample analysis is part of this report. • Sample Analysis 3 i Water samples were analyzed by EPA methods 8021B for BTEX, 5030/Luft for TPHg,and EPA 8260B for Oxygenates. At the request ofEHD 1,2-DCA and EDB were also analyzed by EPA method 8062B. Results of all sample analyses are attached in the original laboratory form and also in recap form (See Water Sample Analysis Recap attached). Findings From Water Sample Analysis The plume concentration has changed from the last sampling event.MTBE concentrations in monitoring well GMX-1 have lowered from 14 ug/L on the last event to2.6 ug/L, and the TPHg on this event has lowered to 8.4 mg/L from 10 mg/L. The only monitoring wells above the non-detect level for MTBE were GMX-1 and MW-3. The concentrations of TPHg in wells GMX-1, and MW-3 have lowered for this sampling event. The groundwater surface has lowered about +/- 0.5' from the last event (see Del-Tech Field Report, enclosed). The groundwater hydraulic gradient is to the south at a slope of S-0.002. Conclusions MTBE above detectable levels only occurred in monitoring wells GMK-1 and MW-3 and at rates less than 15 ppb. Groundwater elevations have lowered from the last event about.5',which is about.7' lower than the same quarter last year. The water sample analysis for monitoring well GMX-1,MW-2 and the extraction well EW-1 continue to produce low levels of TPHg (see Water Sample Analysis Recap • attached). The natural attenuation of all analytes continues at 10% to 20% per year due in part to the yearly groundwater elevation cycles. 2