SITE INFORMATION AND CORRESPONDENCE

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k DIETz ENGINEERING AND CONSTRUCTION, INC. 1 120 HOLLYWOOD AVENUE.SUITE 3,OAKLAND,CALIFORNIA 94602 Notice: Pending Closure of the Leaking Underground Storage Tank (UST) Case at 7500 W. 11th. Street, Tracy CA 95304-9305, the former Navarra Property, by the San Joaquin County Environmental Health Department (EHD), Site Code: 1392 An investigation and characterization of the impact from an unauthorized release from a former UST system on the above referenced site has been completed under the regulatory oversight of the EHD. The EHD has concluded that the investigation and characterization of the release has been completed and is adequate to determine that there is no longer a significant health risk or hazard to the public or to the environment associated with this release and is considering closure of the case. The EHD will be accepting and considering comments from the public regarding the pending case closure for a 60-day period from December 1, 2012 through January 29, 2013, before proceeding with the case closure. Comments should be directed to.Mr.Nuel Henderson by mail at 1868 E. Hazetton Ave., Stockton, CA 95205, by phone at(209)468-3436,or by email at nhenderson@sjcehd.com. History: The property at 7500 West.Eleventh Street in Tracy was used as a fueling station for trucks and other vehicles from circa 1930 until 1998. In 1998 the fueling station was closed and all underground fuel storage tanks were removed from the site. When the underground tanks were removed it was found that buried piping beneath the fueling station pump island had leaked and released diesel and gasoline fuel into the underlying soil and groundwater. In some areas of the site approximately 2000 gallons of the released fuels were found to be floating on the groundwater; the floating fuels were removed by suctioning into vacuum trucks and transported for recycling for beneficial use. Following removal of the underground storage tanks, an extensive program of site characterization and groundwater-quality monitoring was undertaken under the direction and oversight of the EHD. Those investigations found that a plume of'contaminated groundwater extended some 1000 ft. to the north northeast down the groundwater gradient from the 7500 West EIeventh Street site to a point close to the intersection of Chrisman :Road and Carmelo Avenue. The contaminants in the plume include diesel and gasoline and the gasoline components benzene, toluene, ethyl benzene,xylene isomers,ter -butyl alcohol, tert-amyl methyl ether and methyl tertiary butyl ether(MTBE). Current Status of:Plume of Contaminants: Following removal of the fuels floating on the groundwater, the concentrations of contaminants in the plume have been decreasing due to natural processes of attenuation which include natural bioremediation. Figure 1, which is attached, shows the current extent of the area affected by diesel and gasoline and the fringe of MTBE that extends beyond that due to MTBE's greater mobility in the underground. Analyses have shown that the components of the hydrocarbon fuels in the subsurface do not pose a risk,to human health. The plume is now stable and contaminant concentrations are now sufficiently low and the rate at which they are being reduced by natural attenuation is sufficient for the California State Water Resources Control :Board to have recommended that no further active remediation or groundwater-quality monitoring need be undertaken. Projected Future Status of Plume of Contaminants: As the processes of natural remediation continue to reduce the concentration of contaminants in the plume, its area will be further reduced and it is estimated that no contaminants will be detectable in the groundwater within 15 years from 2012. DJW 11/16/12 TELEPHONE:OAKLAND,CALIFORNIA(51 O)336-9118 TRACY,CALIFORNIA(209)832-2910