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NEWt' ! Union ice Company_ Weber Street Report of Findings Page. 3 blows per foot. Clays are classified as medium stiff to hard, and sands are classified as loose to medium dense. 2. Ground water is present beneath this site at a depth of 13 to 19 feet. The first aquifer is semi-confined, and has a gradient of 0.4 feet/100 feet with a S-SE gradient direction. The second aquifer is a confined aquifer also and was encountered at a depth of approximately 51 to 60 feet. The piezometric surface of the lower aquifer is about 6.5 feet lower than the water table surface in the upper aquifer. 3. Hydrocarbon contamination in the soils proved to be minor with low level amounts of xylene and TPH(gasoline) detected between 10 to 15 feet in MW-4S and MW-4I%. 4. Ground water in tete first aquifer below this site has been impacted by gasoline lealdng from underground stor4ge tanks. Ground water in the lower aquifer apparently has not been impacted by this gasoline leakage. 5. Extent of ground water contamination in the first aquifer is undefined as of yet. However, it appears to be Iocalized in the area around MW-4S. l,,au GC,rt YOI/ SSS. 3.2 Recommendations 1. The extent of soils and ground water hydrocarbon contamination at this site should be further defined by a soils vapor survey. A request to perform this survey was presented to San Joaquin County Enviro ealth _� 4—c�c. S Department on June 5, 1990. A copy of the proposed soil vapor survey r sampling locations is presented in this report in map format as Appendix D. 2. Soils contamination at this site should be defined by sampling, during the remedial excavation. A geologist should supervise the sampling of the excavation and definition of the vadose zone contamination. 3. Because of ground water sampling discrepancies, monitor wells at this site should be re-sampled on a quarterly basis until 3 internally consistent sets of data are obtained.