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EXECUTIVE SUMMARY Remediation of hydrocarbon-contaminated soil at Valley Motors(800 East Main in Stockton, California)was initiated in December 2005 A 500-cfrn thermal oxidation vapor extraction unit was connected to vapor extraction well VT-1 and the system went on line on December 12 Startup was witnessed and approved by personnel from the San Joaquin Valley Air Pollution Control District The extraction system operated for 481 hours between December 12 and January 19, 2006, extracting and destroying approximately 300 pounds of hydrocarbon vapors Vapor concentrations were measured weekly in the field with a portable photo-ionization detector, and laboratory samples were collected monthly(December 12 and January 12) Groundwater samples were collected from seven of the eight monitoring wells on January 12, 2006 One well was dry and could not be sampled The samples were analyzed for gasoline and its volatile aromatic compounds (BTEX), diesel, gasoline oxygenates, ethylene drbromide, 1,2-dichloroethane, and total lead Low molecular weight hydrocarbons that elute within the gasoline range and are reported as Total Petroleum Hydrocarbons as gasoline (TPH-g) were detected in six of seven wells, but the laboratory noted that the elevated result was due to a single compound within the gasoline range Very low concentrations of gasoline compounds (benzene, toluene, xylene, etc) were detected in VM-1 and VM-3 Higher concentrations (2,000-5000 parts per billion) were detected in VM-2 The concentration of these low molecular weight hydrocarbons continues to decline No gasoline oxygenates were detected in any of the samples, and neither were ethylene drbromide or dichloroethane However, lead was detected in several wells at,concentrations ranging from 45 to 80 ppb Heavier hydrocarbons that elute within the range of diesel fuel(TPH-d) were reported in VM-1 and VM-2, but the chromatograms were not typical of diesel fuel We recommend deleting TPH-d and oxygenates from the analytical protocol The water table sloped eastward from 20 to 20 5 feet below sea level, which was fairly similar to the situation in November This implies that the groundwater flow direction continues to be east