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PUBLIC HEALTH SERVICES <br /> SAN JOAQUIN COUNTY <br /> ENVIRONMENTAL HEALTH DIVISION <br /> Karen Furst, M.D., M.P.H., Health Officer <br /> 304 East Weber Avenue, Third Floor • Stockton, CA 95202 c;Fovt <br /> 209/468-3420 <br /> D r <br /> BUTCH SCHMIDT o <br /> STOCKTON UNIFIED SCHOOL DISTRICT (SUSD) <br /> 1932 EL PINAL DRIVE JUL 01 <br /> STOCKTON CA 95205 1999 <br /> RE: FRANKLIN HIGH SCHOOL SITE CODE: <br /> 300 NORTH GERTRUDE AVENUE <br /> STOCKTON CA 95206 <br /> San Joaquin County Public Health Services, Environmental Health Division <br /> (PHS/EHD) has reviewed Summary Report of Additional Subsurface Investigation dated <br /> June 1, 1999 prepared by ATC Associates, Inc (ATC) for the above referenced site. A <br /> soil boring was advanced to 62 feet below surface grade (bsg) through the area of the <br /> former 500-gallon underground storage tank (UST) at the above referenced site on <br /> February 24, 1999, and was subsequently converted to a monitoring well (MW-1). <br /> Analytical results of soil samples collected from MW-1 at 25.5 feet bsg were 272 parts <br /> per million (ppm) of Total Petroleum Hydrocarbon as gasoline (TPH-g), 1.70 ppm of <br /> Ethyl-benzene, and 11.3 ppm of Xylenes. Analytical results of all soil samples were <br /> non-detect at above detection limit for Benzene. The analytical result of the soil <br /> sample collected at 55.5 feet bsg was 0.00752 ppm of Methyl tert-Butyl Ether (MTBE). <br /> The analytical result of the water sample collected from MW-1 was 51.4 parts per <br /> billion (ppb) of MTBE. Depth to groundwater was measured to be at 54.84 feet bsg. <br /> PHS/EHD staff noted very strong hydrocarbon petroleum odor in the soil from 10 <br /> feet bsg to 40 feet bsg during the installation of MW-1 on February 24, 1999. The field <br /> screening tool[photo-ionization detector (PID)] recorded 1,000 ppm in the soil sample ; <br /> taken at 20 feet bsg, but dropped to 30 ppm at 30 feet bsg and 11 ppm at 55 feet bsg. <br /> PHS/EHD agrees with the report that the impacted soil seems to be generally limited <br /> to the upper 25 feet of soil. However, analytical results have indicated the presence of <br /> MTBE at 55 feet bsg. This is consistent with the hydrocarbon petroleum odor noted <br /> in the soil as deep as 40 feet bsg, PID reading at 55 feet bsg, and MTBE impact in <br /> groundwater. MTBE and trace petroleum product seems to have leached through the <br /> soil to at least as deep as 55 feet bsg and impacted the groundwater. At this phase of <br /> y the investigation, the lateral extent of the contamination in the soil has not been <br /> defined. However, MW-1 should be sampled for another quarter for confirmation <br /> before PHS/EHD requires further investigative work. <br /> ky` <br /> A Division of San Joaquin County Health Care Services <br /> -4 <br />