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Soil and Groundwater Investigation Quik Stop No 121 Page 6 a state-certified laboratory located in South San Francisco, California The soil and groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHG), benzene, toluene, ethylbenzene, and total xylene (BTEX) and methyl-tertiary-butyl-ether (MTBE), using EPA Test Methods 8015 and 8020 In addition, the five groundwater samples were analyzed for oxygenates, using EPA Test Method 8260 The laboratory reported 20 of the 21 soil samples to be free of detectable petroleum hydrocarbon contamination Soil sample GP-5-28 was reported by the laboratory to contain 0 005 milligrams per kilogram (mg/kg) of toluene No other compounds were detected The laboratory reported 4 of the 5 water samples to be free of detectable TPHG/BTEX Water sample GP-1W was reported to contain 800 micrograms per liter(ug/l) TPHG, 8 ug/1 benzene, 85 ug/l toluene, 16 ug/I ethylbenzene and 83 ug/1 total xylenes The laboratory also reported 2 of the 5 water samples to contain MTBE Water samples GP-1W and GP-2W were reported to have 73 ug/l and 7 ug/l MTBE, respectively No other oxygenates were detected in these water samples Tables 1 and 2 summarize the soil and water analytical results Copies of the laboratory analysis are attached in Appendix D Discussion CCI has collected soil and groundwater samples from 5 location around the former fuel tank area at Quik Stop Market No 121 in an attempt to determine the extent of petroleum hydrocarbon contamination discovered at the site in March 1998 Prior to the start of any field work, a 2,000-Foot Radius Well Survey was conducted in an attempt to locate nearby domestic, municipal, agricultural or irrigation wells that could be impacted by groundwater contamination detected during the fuel tank removal The Survey found 4 such wells to be located within the 2,000-foot radius search area These 4 wells are screened at depths greater than 50 feet The closest well is located approximately 250 to 300 feet west of the subject sites fuel tank area Continuous core soil samples collected at all 5 onsite locations indicate the near-surface soil, to a depth of 8 feet, consists of silty sand, with a more granular material lying between 9 and 20 feet in 4 of the 5 sample locations A stiff silty clay to sandy clay was encountered between 14 and 20 feet on the south side of the property These soil descriptions were generally confirmed with geotechnical laboratory testing for porosity and specific gravity on three selected soil samples From 22 to 30 feet, alternating sequences of silty sand, sand and occasional clay lenses were noted The contact between these various units was gradational • In general,the laboratory data indicates that soil contamination was not detected in any of the 21 soil