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In the site area, groundwater is shown on county flood <br /> control maps to exist at a depth of about 70 to 80 feet, which <br /> is an elevation of about 45 to 55 feet below sea level, Local <br /> Pumping of the shallow water bearing zones is believed to be <br /> responsible for this deeper - below sea level - groundwater <br /> condition. <br /> Several water wells exist in the site area as shown on <br /> Plate 3. Names and addresses of the well owners are not <br /> available at this time. The construction details of each well <br /> are similarly not available. Based on our brief observations of <br /> the size and structure of the pumping systems, the wells appear <br /> to be deriving water from relatively shallow depths. one well <br /> located 1/4 mile south of the site, however, was apparently <br /> pumping large quantities of water from presumably much deeper <br /> water bearing zones. <br /> V. REVIEW OF LABORATORY ANALYSIS OF SOIL SAMPLES <br /> Two sets of chemical test data were available for the tank <br /> removal and soil excavation efforts. One was from the original. <br /> tank removal effort in 1989, and the other was for additional <br /> soil excavations in 1990. The 1989 tests were performed by <br /> California Water Labs of Modesto, California and the 1990 series <br /> by Geoanalytical Labs, also of Modesto. Both sets of samples <br /> were collected and transported by SEMCO of Modesto, California. <br /> Sample locations and results for the 1989, original tank <br /> removal effort are difficult to interpret. On Plate 4A, the <br /> approximate, and to some extentresumed of the <br /> collected and tasted are shown.P These position <br /> samples <br /> esultsgenex llyhow <br /> Total Petroleum Hydrocarbons as gas and diesel in the tank <br /> excavatio:, oil and diesel in the approximate area of the fuel <br /> Islands, and diesel in the initial stockpiled soils. Plate 4A <br /> shows the test result next to the location. Copies of available <br /> test results performed by California Water Labs are presented in <br /> Appendix A. <br /> A total of 19 soil samples were tested by GeoAnalytical <br /> Labs for Total Extractable Petroleum Hydrocarbons, Benzene- <br /> Toluene-Xylene-Ethylbenzene. The results of these tests are <br /> shown below: <br /> 4 <br />