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i <br /> 4 ^\ <br /> PUBLI HEALTH SEkCLS <br /> SAN JOAQUIN COUNTY <br /> ENVIRONMENTAL HEALTH DIVISION <br /> Karen Furst, M.D. <br /> M.PH., Health Officer <br /> 304 East Weber Avenue, Third Floor • Stockton, CA 95202 �'�'►Fos��'�P <br /> 209/468-3420 <br /> CARL NAVARRA JUL O 3 2001 <br /> 475 BLEWETT ROAD <br /> TRACY CA 95376 <br /> _ 1 <br /> RE: Navarra Property <br /> 7500 Eleventh Street SITE CODE: 9392 <br /> Tracy CA 95376 <br /> t <br /> San Joaquin County Public Health Services, Environmental Health Division (PHS/EHD) has <br /> reviewed the Site Characterization Report (report) dated January 2001 that was Prepared by <br /> The San Joaquin Company Inc. (SJC) on your behalf and has the following comments. <br /> The report documents site characterization fieldwork that took place in April 2000, when <br /> fourteen direct push soil borings and seven groundwater monitoring wells were installed <br /> on <br /> site. Soil samples for analysis were collected during the advancement of the soil borings <br /> during the drilling of the monitoring wells. Grab groundwater samples were collected from <br /> the soil borings, and from the monitoring wells following development. g <br /> and <br /> Analytical results from the soil samples indicate widespread low-level petroleum hydrocarbon <br /> contamination at depths to twenty-eight feet below surface rade bs <br /> contaminant concentrations were found on the southern edge of the property, i y ocarbon <br /> at 3,800 milligrams per kilogram (mg/kg) total petroleumg ( g} The highest <br /> A high concentration of TPHg was also found in boring PP-14, located n boring PP-7 <br /> hydrocarbons as gasoline (TPHg}. <br /> tank pits and the former dispenser island area. The report attributes the cause of <br /> between the former <br /> spread nature of the soil contamination to a series of chronic minor leaks ands ills e <br /> occurred as a byproduct of the trucking activities that historically occurred the wide <br /> P at likely <br /> Analysis of groundwater samples from the site show high levels of co on site. <br /> groundwater in several of the wells and grab groundwater samples. The report con <br /> that two plumes of contamination exist at the site, one emanating contaminant impact to . <br /> former dispenser island and piping lines, and one emanatingfrom dudes <br /> Ing from the area near the <br /> the property, whose source is unknown. Monitoring well M -3, locatedar the southern edge of <br /> dispenser island area, had 11 1 000 micrograms per liter <br /> se to the former r <br /> tertiary butyl ether(MtBE}. and 10, <br /> Well MW-4 located on site and/e east ogMW 3 had Ag/l methyl <br /> and 990 µg/1 MtBE. Well MW-7, located across the street to the north of the site, <br /> µg/1 TPHg and 22 µg/! MtBE. Groundwater flow direction was d 52 p'g/1 TPHg � <br /> northeast. These results indicate that the vertical extent of the contaminante' had 1,400 <br /> been defined, or the lateral extent towards the downgradient calculated to be towards the <br /> plume has not <br /> g client direction. <br /> 1 <br /> r <br /> l <br /> I <br /> r <br /> A Division of San Joaquin County health C- <br />