ARCHIVED REPORTS XR0006460 - Laserfiche WebLink

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Site No: 19192 Although the complete extent of contamination is not known at this time, there is sufficient evidence to demonstrate that the site was contaminated before the time of Tosco's purchase. The areas at the site for which evidence of contamination exists are: the former gasoline and motor oil UST complex areas, former product line locations, and former pump islands area. Soil samples collected from the former gasoline and oil UST complex and product line excavations, and from borings MW-3, MW-7, and VW-2 contained one or more of the following at concentrations above method detection limits: TPH-G, BTEX, TPH-D, TOG, EDB, and metals. Groundwater samples taken from wells MW-1, MW-3, and MW-7 and from HydroPunch borings HP-1, HP-5, THP-3, and THP-4 demonstrated the presence of one or more of the following at concentrations above method detection limits: TPH-G, BTEX, and 1,2-DCA. The extent of evidence of actual contamination levels present and the evidence of sources of contamination consists of: Soil and groundwater data as summarized earlier in this report and detailed in existing files o Results from Target's 1989 soil gas survey A release report filed with San Joaquin County in 1989, based on soil gas data Documentation that gasoline contamination in the former fuel UST excavation appeared to be widespread ® Documentation that horizontal and vertical vapor extraction lines were installed at the site • A soil vapor extraction pilot test conducted at the site in 1992 In conclusion, existing and developed evidence establishes a contamination baseline consisting of the measured presence of hazardous substance contamination in soil and groundwater and evidence of historic sources and release of hazardous substances. This report establishes a contamination baseline consisting of: 1. Known area of contamination from measured or observed direct evidence, and BrTOS/RPT/11192RPI'.d07-94/LAM/1b:5 0952-090.03 7Rev.0, 12/27194