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indicated that the point of loss was located under the cement slab at the pump islar.d. On May 6 and 7 1986, four monitoring wells were installed to assess the lateral and vertical extent of the contamination. Due to free product accumulations within wells WW 1 and 4 a bailing program was initiated May 8, 1986, at the request of the San Joaquin Local Health District. Subsequently a small diameter double pumping system was installed in well 4 to initiate some control over continued migration of free product and provide for continuous collection of accumulated product. Groundwater underwater pumped from this well is treated by carbon filtration prior to discharge to the sanitary sewer system. In excess of 430 gallons of free product has been recovered from wells 1, 3 and 4 through August 1986 by the bailing and pumping programs. Five additional monitoring wells were installed in late May to early June to further define the lateral extent of - � contamination. Water samples from these wells and nearby domestic wells were analyzed to determine the degree of dissolved hydro- carbon contamination and assess potential impacts to the domestic wells. Although initial laboratory results suggested the presence of dissolved hydrocarbons in some wells tested, four subsequent sample rounds including one round conducted by the San Joaquin Local Health District, indicate that none of the domestic wells sampled have detectable concentrations of dissolved hydrocarbons to date. SITE CONDITIONS _M SITE SETTING The study area is situated within an alluvial basin in the central portion of San Joaquin County. The project site is located approximately 6 miles north .of downtown Stockton on relatively flat topography at an elevation of 11 feet above sea level. The 7-Eleven Store has 3 underground storage tanks and 1 2