SITE INFORMATION AND CORRESPONDENCE FILE 1

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California Tank Lines, Inc. Page 3 3105 South El Dorado Street January 12, 2009 Stockton, California 95206 WRM has recommended the following: • Prepare a human health risk assessment that includes a sensitive receptor survey. • Conduct a soil vapor survey. • Prepare a natural attenuation assessment to determine the time needed for natural attenuation to achieve water quality objectives. • Review chromatograms of TPHg and TPHd and mass spectra data from all four monitoring wells for comparison of similarities and differences, and indicators of weathering. • Prepare a closure report if results from the above recommendations demonstrate acceptable levels of risk. The EHD approves preparation of a human health risk assessment and a sensitive receptor survey report that includes surface water bodies, schools, as well as domestic, municipal, industrial and other wells within a 2,000-foot radius of this site. Contact the Department of Water Resources, municipal water suppliers, and nearby industries for well information. Perform a physical search of the area to identify all wells, and show the location of all wells on a map, relative to the location of this site and submit any known construction details of the wells to the EHD by March 4, 2009, The Central Valley Regional Water Quality Control Board is requiring evaluation of Environmental Screening Levels (ESLs), California Human Health Screening Levels (CHHSLs), San Francisco Bay Regional Water Quality Control Board) and the potential for vapor intrusion into buildings for closure consideration of sites having residual contamination left in place; therefore, the EHD concurs that a soil vapor survey is warranted that includes the evaluation of ESLs, CHHSLs, and the potential for vapor intrusion into the existing onsite buildings . Submit to the EHD by March 4, 2009, either a work plan to assess the potential for vapor intrusion into the existing onsite buildings, or a rational, with technical support, for discounting vapor intrusion into the buildings as a potential hazard for this site. Based on high concentrations of TPHg, benzene, and 1 ,2-dichloroethane ( 1 ,2-DCA) detected in groundwater from boring P2 at 35 feet bsg; the possible high concentrations of 1 ,2-DCA detected in groundwater from boring S-5 at 65 feet bsg; high concentrations of TPHd and TPHmo detected in groundwater collected from MW-2, and high concentrations of TPHg, benzene, and 1 ,2-DCA detected in groundwater collected from MW-4 during the quarterly groundwater monitoring events, instead of submitting a natural attenuation assessment, the EHD directs that a corrective action plan be submitted to the EHD by April 6, 2009, that includes several methods for site remediation. Please include contaminant mass estimates, supported by calculations, for sorbed and dissolved TPHg, benzene, 1 ,2-DCA, TPHd, and TPHmo. The recommended remedial technology should be well supported by an analysis for cost- effectiveness .