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The laboratory is currently preparing electronic data files for submittal to Geotracker Geocon will upload the data and provide Caltrans with a Geotracker confirmation number as soon as the process is complete Groundwater Analytical Results TPHg was detected in samples collected from wells MW-14, VM-1 and VM-2 at concentrations of 2,900, 970 and 4,400 µg/I, respectively TPHd was detected to the groundwater samples collected from wells MW-14 and VM-2 at respective concentrations of 110 and 1,500 µg/1 Benzene was detected in the groundwater samples collected from wells MW-14, VM-1 and VM-2 at concentrations of 820, 240 and 1,500 µg/l, respectively Toluene was detected in the samples from wells MW-14 and VM-2 at respective concentrations of 68 and 92 µg11 Ethylbenzene and total xylenes were detected in wells MW-14, VM-1 and VM-2 at concentrations ranging from 43 µg/1 (VM-1 - total xylenes) to 470 µg/1 (MW-14 - total xylenes) FOCs were not detected above their respective laboratory method detection limits in each of the groundwater samples TPHg, TPHd and benzene concentrations for the Fourth Quarter - 2003 monitoring event are depicted on Figure 3, Petroleum Hydrocarbons in Groundwater - November 2003 CONCLUSIONS AND RECOMMENDATIONS The highest concentrations of dissolved phase petroleum hydrocarbons appear to be limited to the immediate vicinity of the former UST excavation area (monitoring wells MW-14, VM-1 and VM-2) Geocon recommends that the Central Valley Regional Water Quality Control Board (CVRWQCB) consider the Site for possible low risk closure and regulatory "no further action" status Pending evaluation by the CVRWQCB, the next quarterly monitoring event is scheduled for February 2004 • If there are any questions concerning the contents of this report, or if Geocon may be of further service,please contact the undersigned at your convenience Sincerely, GEOCON CONSULTANTS,INC Ali AZ PE, CEG Rebecca L Silva, REA >rooManagcr No 46681 Project Scientist * EXP 06/30/07 RLS JEJ res (5) Addressee OFCAL1Fa Attachments Figure 1, Vicinity Map Figure 2, Groundwater Elevation Map -November 2003 Figure 3, Petroleum Hydrocarbons in Groundwater-November 2003 Table 1, Summary of Groundwater Elevation and Analytical Data Appendix A, Summary of Historical Groundwater Analytical Data Appendix B, Monitoring Well Sampling Data Sheets Appendix C, Laboratory Reports and Chain of Custody Records Prosect No 58475-06-241 -3- December 29,2003