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EXECUTIVE SUMMARY Six soil borings were drilled in February 2003 to further assess the extent of the impact to groundwater from petroleum hydrocarbons at 8125 South El Dorado Street in French Camp, California The'site is the location of J & L Market, a gasoline service station, restaurant, and convenience store Eighteen soil samples and eight water samples were collected for laboratory analysis Two borings were drilled at an angle of 20° from vertical, reaching a vertical depth of 28 feet at a point approximately 6 feet beneath the service station building Gasoline- impacted soil had previously been sampled near the building, and the purpose of these borings was to determine how far this contamination extends beneath the building Slightly impacted soil was drilled in one of these borings Total Petroleum Hydrocarbons in the gasoline range were detected at a concentration of 8 2 milligrams/kilogram (parts per million) Toluene was detected slightly above the detection limit, but no other hydrocarbons were reported Two other borings were drilled to a depth of 30 feet near the former underground storage tank facility Four soil samples were preserved for laboratory analysis, but no hydrocarbons were detected The last two borings were drilled to a depth of 40 feet, near the base of the first aquifer sand, and eight samples were analyzed One sample contained heavier hydrocarbons (aged gasoline or diesel) at a concentration of 4 mg/kg, but no other evidence of contamination was observed One or more hydrocarbons were detected in all eight water samples The laboratory reported concentrations ranging from 71 to 840 micrograms/liter (parts per billion) in the range of overlap between gasoline and diesel, and noted that kerosene-range compounds were significant in two of these, oil-range compounds were significant in two others, and gasoline was significant in one Gasoline concentrations ranged from 77 to 170 ppb, and the laboratory noted that the chromatograms suggest aged gasoline Benzene was absent in all water samples, and all related volatile organic hydrocarbons (toluene, etc ) were near or below the detection limit as well, supporting the interpretation that the hydrocarbons represent aged and degraded gasoline rather than diesel fuel Three fuel oxygenates (MTBE, DIPE, and TBA) and 1,2-DCA were detected in various samples, but all MTBE concentrations were below the taste and odor threshold of 14 ppb 5 Soil samples collected in this and previous phases of this investigation were used to contour the distribution of gasoline hydrocarbons in the soil The impacted area is limited to the north end of the station building, and encompasses an area measuring 18 feet by 42 feet The depth of the impact ranges from 10 to 30 feet, with the highest concentrations isolated within a relatively dense clay bed from 15 to 26 feet The water samples collected from the six new borings have been combined with those . collected in January 2003 from the three existing monitoring wells and those collected in 1