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A2 -- Results Report - Soil and Ground Water Investigation March 1996 (9647-0011) ' This report documents the methods of investigation, findings, and conclusions of the soil and ground water investigation conducted at 26500 Nowell Road, Thornton, California (subject property) The site location and site maps are shown on Figures I and 2 The environmental ' investigation was conducted by Fugro on behalf of Pamela Lopez Purpose and Scope 1 The purpose of the investigation was to assess soil and ground water conditions at the location of a former 500-gallon-capacity underground storage tank (UST) used to store gasoline ' The UST was removed in October 1989 The scope of the soil and ground water investigation was limited to the advancement of five drill holes in the vicinity of the former UST Three of the drill holes were completed as ground water monitoring wells Soil and ground water samples were analyzed for total petroleum hydrocarbons as gasoline (TPH-g) and benzene, toluene, ethylbenzene, and xylenes (BTEX) Backgi,ound The subject property is a private residence located on the east side of Nowell Road in a rural portion of Thornton, California Adjacent to and south of the property is a Tri-Valley I Growers canning facility The canning facility includes former USTs and a forklift shop within 50 feet of the southern boundary of the subject site ' The subject site was purchased by Ms Lopez in 1979 with an existing 500-gallon-capacity gasoline UST on the property According to the previous owners, the UST had not been used for ten to 15 years On October 9, 1989, the UST was removed One soil sample was collected from the bottom of the excavation and analyzed for TPH-g and BTEX The results indicated that a release of petroleum hydrocarbons had occurred The analytical results are presented in Table 1, Summary of Results of Analyses Soil Samples - Previous Investigations In November 1994, three soil borings were drilled and sampled at the subject site by RAH Environmental, Inc (Figure 2) Soil borings SB-3 and SB-4 were drilled in conjunction with a I subsurface investigation of the adjacent Tri-Valley Growers property, and boring SBA was drilled through the former UST location at the subject site to evaluate the vertical extent of the release Soil samples collected from the soil borings were analyzed for TPH-g and BTEX TPH-g and BTEX concentrations were not detected at or above the laboratory detection limits in soil samples collected from soil borings SB-3 and SB-4 Chemical analysis of the soil samples collected from soil boring SBA detected petroleum hydrocarbons in the soil sample collection below the water table The analytical results are presented in Table I • 96470011396 1