SITE INFORMATION AND CORRESPONDENCE

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Former Vernalis Pump Station -2 - 19 March 2004 Bellini and Arcos Properties San Joaquin and Stanislaus Counties PREVIOUS INVESTIGATION RESULTS The purpose of the investigations was to determine the lateral and vertical extent of impacts to soil and groundwater caused by petroleum hydrocarbon leaks from abandoned crude oil pipelines, the OVP and the former pump station operations. The approximately 5.73 acre Bellini site, is located in a rural light industrial area at Welty Road and Highway 33, south of Vernalis. The Arcos site is approximately twice the size of the Bellini property. Both sites, owned by the Bellini and Arcos families, are adjacent and the common property boundary between the sites is the San Joaquin and Stanislaus County line. In 1995, a consulting firm conducted an environmental assessment of the Bellini site for Chevron, to - evaluate site conditions and establish the history of the facility and surrounding properties. In 1995 and 1998, soil samples were collected from eight borings. The four existing groundwater monitoring wells were installed in 1998. Six additional borings were drilled by Geomatrix in 2002 to collect soil samples, one grab groundwater sample and sample the groundwater wells. Depth to water has ranged from approximately 31 to 37 feet and flowed generally east to northeast. Soil Between 1995 and 2002, numerous samples were collected from the soil borings and analyzed for total petroleum hydrocarbons (TPH) as diesel, gasoline, motor oil, and/or crude oil (TPH-d, TPH-g, TPH-mo, and TPH-c, respectively), benzene, toluene, ethylbenzene, and xylenes (BTEX) and polyaromatic hydrocarbon (PAH) constituents. The investigation was generally limited to the southeast corner of the Bellini site, next to the former OVP right-of-way. Various TPH constituents were detected in a portion of the soil samples obtained at random depths from the borings located in the same area. The area of drilling was approximately 75 feet north-northwest of the former pump house and boiler house (located on the adjacent Arcos site). 3 According to the analytical results, TPH-impacted soil greater than 1,000 mg/kg occurs between 5 and 46.5 feet, ranging from 2,500 mg/kg at 5 feet in SB-10 to 5,800 mg/kg in MW-1 at 46.5 feet. With the exception of some samples having results slightly above the minimum laboratory detection limits, BTEX and PAH compounds were not detected. However, those low concentrations of BTEX and PAH compounds reported were coincidental with the borings having elevated TPH-d, TPH-c, and/or TPH-mo concentrations. Low concentrations of TPH-9 ranging from 43 to 270 mg/kg were reported in the MW-1 boring (25 feet) and SB-8 (25 feet), respectively. The reports did not indicate if the TPH-g reported was actuallyl "degraded" petroleum hydrocarbon byproducts. Results for samples obtained from 71 to 80 feet were ND for petroleum hydrocarbons. Residual petroleum hydrocarbons are present in soils from MW-4, 180 feet east to the property boundary and offsite. The majority of the onsite borings were in the southeast area of the site as discussed above;