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groundwater levels in the area; depth to groundwater data is not available for the airport but is estimated to be below 75 to 100 feet. 4.1 Pipeline _Borings Borings B-1 through B-5 along the former pipeline trench route were advanced to a depth of three feet into native soil (see Figure 2). The upper one to two feet of material appeared to be mixed silt with gravel fill soil attributed to historic trench backfill material from the UST removal project. The underlying native soil was field classified as sandy silt; groundwater was not encountered in any of these shallow boreholes.- Very low PID reading of soil vapor in the shallow pipeline boreholes ranged from about 1.8 to 8.3 parts per million(ppm); no staining was observed in any soil sample or the drill cuttings. 4.2 Former Underground Tank Pit Excavation Boring B-6 One boring was advanced to a depth of 30 feet within the former tank pit excavation (see attached B-6 Boring Log and Geologic Cross Section Figure 3). The boring revealed sand backfill locally mixed with silt to a depth of about 13 to 14 feet below grade. A piece of what appeared to be visqueen plastic was recovered from a depth of about 5 feet. Native soil consisted of interbedded clayey sand, sandy silt and sand with some fine gravel and occurred from about 14 feet to 30 feet. Soil vapor readings showed that soil vapor was not detected and no staining was observed in the soil. Groundwater was not encountered in the boring. The boring was terminated when the driller called drill rig refusal to advance the drill bit at 30 feet. 5.0 Chemical Analysis Twelve (12) soil samples were analyzed at Kiff Analytical LLC, a State-certified analytical laboratory in Davis, California. All samples were tested for the following; Total Petroleum hydrocarbons as Gasoline (TPHG) and Diesel (TPHD), Benzene (B), Toluene (T), Ethylbenzene (E), Xylene (X), Methyl-tert-butyl-ether (MTBE), and fuel oxygenates tert-Amyl-Methyl-Ether, Ethyl-tert-Butyl-Ether, Di-Isopropyl Ether and tert-Butyl Alcohol, 1,2-Dichloroethane (1,2- DCA), Ethylene Dibromide (EDB), and Methanol and Ethanol using EPA Methods 351018015, 8020 and 8260B. The analyses will be performed and a "normal" ten-day turnaround. The analytical reports are attached and the results presented in Table 1 below. 6.0 Results and Discussion The chemical analysis results showed the TPHG, BTEX, fuel oxygenates, 1,2-Dichloroethane, Ethylene Dibromide, Ethanol and Methanol were not detected in any sample (see Table 1). TPHD was detected in the shallow soil samples located along the former pipeline. However these detections were very low ranging from 3.2 to 14 milligrams per kilogram ((Mg/kg). TPHD was detected in the 9-9.5 foot depth at 16 Mg/kg sample in the former tank pit backfill soil. However there were no contaminant detections of any compound in the samples from 15 to 30 feet deep under the tank pit. Page 4 of 7