ARCHIVED REPORTS_THIRD QUARTER 2010 STATUS SUMMARY REPORT

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Stantec Third Quarter 2010 Status Summary Report Former Tosco Bulk Terminal No. 10013 October 26, 2010 stabilized. The Field Data Sheets for the third quarter 2010 sampling event are presented in Appendix D. BC Laboratories, Inc. (BC) accredited by the California Environmental Laboratory Accreditation Program, performed the analyses for this MRP. Samples submitted to BC were tested for combinations of the following analytes: • BTEX by EPA Method 82606; • TPH-d ,TPH-g by EPA Method 8015M; • Oxygenates including MTBE, di-isopropyl ether (DIPE), tert-amyl methyl ether (TAME), TBA, ethyl tert-butyl ether (ETBE), methanol, and ethanol by EPA Method 82606- Modified. Maximum detection limits provided to the laboratory for the analytes are presented in Table 1. Groundwater Analytical Results The field groundwater quality parameters recorded for the wells that were gauged, purged and sampled during the third quarter monitoring event are listed on the Field Data Sheets in Attachment D. The groundwater analytical results for the sampled monitoring wells are presented in Table 4. The analytical laboratory report and chain-of-custody documents are provided in Appendix D. Historical groundwater monitoring results are provided in Appendix B. "A" Zone MTBE and TBA concentration contour maps for the third quarter 2010 are illustrated on Figures 6 and 7. Historical groundwater elevations and chemical concentration trend charts for wells MW-1, MW-2, MW-8 and MW-14 are illustrated on Figures 8 through 11. The following is a summary of the groundwater analytical results for the third quarter 2010: • TPH-g was not detected in any wells samples during the August 30, 2010 sampling event. • TPH-d was detected in 12 of the 14 wells sampled at concentrations ranging from 54 Ng/L (MW-1) to 1,900 pg/L (MW-18C). • MTBE was detected in 7 of the 14 wells sampled at concentrations ranging from 0.60pg/L (MW-22C) to 7.2 pg/L (MW-18C). MTBE concentrations were above the secondary action level of 5 pg/L only in the groundwater samples collected from wells MW-16, MW-176, and MW-18C. • TBA was detected in 4 of the 14 wells sampled at a concentrations ranging from 34 pg/L (MW-11) to 62 pg/L (MW-18C). 4