SITE INFORMATION AND CORRESPONDENCE

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Former Vernalis Pump Station -4- 19 March 2004 Bellini and Arcos Properties San Joaquin and Stanislaus Counties Concentrations of TPH-c between 100 to 400 mg/kg in samples collected at about I and 5 feet were detected in onsite borings SB-16 and SB-17. TPH-c was detected at concentrations between 690 and 39,000 mg/kg in onsite borings SB-15, 16 and 21, and offsite in SB-19 and 20 samples collected at depths of about 56 feet and 67.5 feet. Benzene was not detected, and toluene, ethylbenzene, and xylenes were ND or slightly above the respective minimum laboratory reporting limits. Generally, PAH concentrations were less than 0.02 mg/kg in the 1 and 5 foot samples. PAH concentrations in the deeper samples, between 56 and 67.5 feet, ranged from 0.013 mg/kg (chrysene) to 25 mg/kg (naphthalene). Based on the boring lo.-.s, PID readings, and review of the field data, downgradient boring SB-18 was not impacted from the surface to maximum depth of 70 feet. According to the field observations coupled with the analytical data, it appears that the vertical extent of impacted soil in the southeast corner of the site and near SB-14 has been adequately delineated. - The lateral extent of impacted soil has not been delineated in the vicinity of SB-17 and beyond to the north-northwest portion of the site. Groundwater Depth to first unconfined groundwater is approximately 35 feet, and flow direction is generally east- northeast. TPH-d was detected in onsite grab groundwater samples SB-15, SB-17, and SB-21 at 3,400, 240, and 2,200 µg/L, respectively. A groundwater sample from offsite and downgradient boring SB-18 reported TPH-d at 810 pg/L (soil not impacted). TPH-g and BTEX compounds were not detected in the grab samples. Low PAH concentrations (0.1 to 1.3 pg/L) were detected in two of the onsite borings in groundwater at approximately 45 and 100 feet; the remaining grab samples results were ND for PAH compounds. Since the other two offsite borings (SE of SB-18) were visually impacted with petroleum hydrocarbons, no grab groundwater samples were collected. According to the report, the quality of the groundwater samples collected from approximately 100 feet may have been compromised due to the depth and type of equipment used. Based on the field observations and the analytical results, it appears that the vertical extent of impacted groundwater has been defined. The lateral extent of impacted groundwater has not been adequately delineated offsite, east and downgradient of the existing monitoring wells, on the opposite side of Highway 33. 3 Arcos Property I The Arcos site and the current onsite investigation was to characterize the property in accordance with ChevronTexaco's revised CTA document. Historical aerial photographs, site plans, and a geophysical survey were utilized to focus the Arcos investigation and identify underground features that may have been associated with the OVP or pump station operations. Consequently, soil borings were advanced to collect soil and groundwater samples at 12 locations identified as a geophysical and/or historical site anomaly. Anomalies were identified near