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<br /> Soil Sampling Report - Chevron Service Station #9-3232, Stockton, CA
<br /> April 28, 1999
<br /> Waste Oil UST Removal and Soil Sampling
<br /> On March 11 , 1999, one 1 ,000-gallon single-walled fiberglass waste oil UST was uncovered and
<br /> removed by Wendt. Upon removal, the UST was visually inspected for evidence of failure. Holes
<br /> were not observed in the UST. The UST was removed from the site and disposed of by Ecology
<br /> Control Industries (ECI) of Richmond, California.
<br /> Two soil samples, labeled TK4-N and TK4-S, were collected from beneath the north and south ends of
<br /> the former waste oil UST at depths of approximately 10 feet bgs. Soil discoloration was observed
<br /> beneath the north end of the waste oil UST between depths of approximately 10 and 16 feet bgs.
<br /> Discolored soil was excavated and stockpiled separately on-site for further sampling and disposal . One _
<br /> additional soil sample, labeled TK4-N( 17), was collected from beneath sample TK4-N at a depth of
<br /> approximately 17 feet bgs. Soil sample locations are shown on the attached Figure 2.
<br /> These soil samples were analyzed for TPHg, BTEX, MtBE, Total Petroleum Hydrocarbons as diesel
<br /> (TPHd), Total Recoverable Petroleum Oil (O&G), Halogenated Volatile Organic Compounds
<br /> (HVOCs), polychlorinated biphenyls (PCBs), and the metals cadmium, chromium, lead, nickel, and
<br /> zinc. Sample TK4-N contained TPHg (reported by the laboratory as gasoline and unidentified
<br /> hydrocarbons C&C12) at a concentration of 2 ppm, xylenes at 0. 014 ppm, TPHd (reported by the
<br /> laboratory as unidentified hydrocarbons >C12) at 810 ppm, and O&G at 2,700 ppm. However, after
<br /> additional excavation in the vicinity of sample TK4-N, the additional sample TK4-N(17) collected from
<br /> beneath sample TK4-N at a depth of approximately 17 feet bgs, and sample TK4-S contained no
<br /> detectable concentrations of TPHg, BTEX, MtBE, TPHd, HVOCs, and PCBs. O&G was detected in
<br /> samples TK4-N(17) and TK4-S at concentrations of 79 and 110 ppm, respectively.
<br /> Product Line and Dispenser Removal and Soil Sampling
<br /> On March 11 , 1999, the product dispensers and 2-inch diameter double-wall fiberglass product lines
<br /> were removed. Per the direction of Mr. Kith of the SJCEHD, GR personnel collected four soil
<br /> samples, labeled Dl , D2, D3 , and D4, from beneath the product dispensers at depths ranging between
<br /> 3 . 75 and 4.0 feet bgs. In addition, seven soil samples, labeled PI through P7, were collected from
<br /> beneath the product piping at depths ranging between 3 . 75 and 4. 5 feet bgs. Soil in the vicinity of
<br /> product piping and dispensers consisted of silt and clayey silt. Soil sample locations are shown on the
<br /> attached Figure 2.
<br /> These soil samples were analyzed for TPHg, BTEX, MtBE, and oxygenated compounds by EPA
<br /> Method 8260. Soil samples collected from beneath the product piping and dispensers did not contain
<br /> any detectable concentrations of TPHg, BTEX, MtBE, or oxygenate compounds, except for 0. 0051
<br /> ppm of toluene detected in sample P4, 0. 0093 ppm and 0. 0069 ppm of xylenes detected in samples PI
<br /> and P6, respectively.
<br /> 346463 .03
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