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S. SUMMARY <br /> TWo new monitoring wells were constructed at the site to monitor groundwater at farmer Chev- <br /> ron SS 9-7780. Seven shallower monitoring wells had gone dry after several years of drought <br /> and increased pumping of groundwater in the area,mainly for crop irrigation. <br /> The present level of groundwater is about 70 feet below the surface under the site--a drop of 30 <br /> feet since March 1987. Two wells, EAS and EA6, were installed at the site boundaries(Figure <br /> 4) on a line between the potential source of hydrocarbons(the former tank field) and nearby <br /> domestic water supply wells. Eleven soil samples collected from the two boreholes between a <br /> depth of 30 feet and the water table(70 feet)were analyzed for total petroleum hydrocarbons and <br /> aromatics (benzene,toluene,ethylbenzene, xylenes). No concentrations of petroleum hydrocar- <br /> bons above the respective detection limits were found in soil samples. <br /> Groundwater samples were also collected and analyzed for the same fuel components, and <br /> concentrations did not exceed the detection limits for these constituents in the samples. <br /> The monitoring wells (MW 1, MW2,MW3)installed by GTI around the former tank field,which <br /> have been dry since February 1989,and whose tops were in bad condition,creating a potential <br /> path for direct surface water infiltration and aquifer contamination,were destroyed at the request <br /> of the Satz Joaquin County Local Health District. The wells were destroyed in accordance with <br /> . the appropriate state Guidelines,Bulletins 79-81 and 88-81 (DWR 1981, 1988). <br /> c67f977801tx 7 <br />