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indicated that the point of Joss was locntod under the cemon, slab at the pu7v island. Oh May 6 and 7 1986 , four mcnitorina wells were inst" l.led to assess the lateral. and vertical oxtcnt of the contaminat:icn. Due to free product accumulations within wolls 1 and 4 a bailina program was initiated May 8, 1986, at the request of the Sar 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 c,rhon filtration prior to discharge to the sanitary sewer system. in excess of 430 gallons of free product has been recovered frons wells I, 3 and 4 through August 1986 by the bailing and numr_ino programs. Five additio ,,l.l monitoring wells were installed in latae May to early June to further define the lateral extent cf 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 Pistrict, indicate that none of the domestic wells sampled have detectable concentrations ai dissolved �. hydrocarbons to date. SITE CONDITIONS _. 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 tc ?ography at an elevation of 11 feet above sea level. The 7-Eleven Store has 3 underground storage tanks and 1 ?. I