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r Jeffrey Baker Tesoro Petroleum Site No. 67077 April 23, 2004 Page 2 lithologic description were also field measured for volatile organic compounds using a photo-ionization detector (PID) and recorded on the boring log. Field methods and procedures used by Delta during installation of the soil borings are summarized in Enclosure A. Soil boring logs are presented in Enclosure B. Two soil samples from each boring were submitted to Kiff Analytical LLC (Kiff Analytical) of Davis, California, for analysis of benzene, toluene, ethylbenzene, and total xylenes (BTEX), methyl tertiary butyl ether,tertiary butyl alcohol, tertiary amyl methyl ether, di-isopropyl ether, and ethyl tertiary butyl ether (oxygenates), 1,2-dichloroethane and 1,2-dibromoethane (lead scavengers), and total petroleum hydrocarbons in the gasoline range (TPHg) using EPA Method 8260B. The Kiff laboratory report is presented in Enclosure C. Results Soil borings were advanced near the fuel tanks and dispenser islands at the locations shown on Figure 2. Screening of soil samples with a PID did not detect the presence of volatile organic compounds. The PID results are presented on the soil boring logs included in Enclosure B. Most of the PID results were zero with a few results of 0.5 to 1.0 part per million volume (ppmv). These readings are considered background. No odor or petroleum staining was observed in soil samples. The soil borings were not advanced to groundwater because field screening of soil samples did not detect petroleum hydrocarbon contamination. The bottom soil sample and one sample from 5 to 17 feet from each soil boring were submitted to Kiff Analytical for chemical analyses. With the exception of one analysis, Kiff Analytical did not detect BTEX, oxygenates, lead scavengers, or TPHg at or above the reporting limits. The laboratory analysis of the soil sample from boring B-5, collected at 30 feet bsg identified TPHg at 1.1 milligrams per kilogram. This is not considered to be a significant concentration. Furthermore, Kiff Analytical reported that the concentration was not typical of gasoline based on the observed chromatographic pattern. The laboratory chemical analyses results are summarized in Table 1 and the laboratory report presented in Enclosure C. Disposal of Drill Cuttings One drum of soil cuttings generated during drilling activities was placed onsite. On April 9, 2004, Integrated Waste Management Inc.,of Milpitas,California removed the drummed soil from the site. Recommendations Delta did not encounter evidence of a fuel leak during the baseline assessment work performed at the site. Delta concludes that no further actions are needed at this site. Remarks The recommendations contained in this report represent Delta's professional opinions based upon the currently available information and are arrived at in accordance with currently acceptable professional