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4.0 Chemical Analysis—GeoProbe Samples Twelve (12) soil samples and six (6) groundwater samples ftom the GeoProbe. borings were analyzed at Kiff Analytical LI-C, a State-certified analytical laboratory in Davis, California. All samples will be tested for the following; Total Petroleum hydrocarbons as Gasoline (TPHG) and Diesel (TPHD), Benzene (B), Toluene (T), Ethylbenzene (E), Xylene (X), Volatile Organic Compounds (IOC), Methyl-tert-butyl-ether (MTBE), and fuel. oxygenates tert-Aixiyl-Methyl- Ether (TAME), Ethyl-cert-Butyl-Eller (ETBE), Di-Isopropyl Ether (DJ11E) and tert-Butyl Alcohol (TBA), 1-2, Diehloroethane (1-21)CA), Ethylene DiBromide (EDB) and. Ethanol (F_,th) and Methanol (Meth) using EPA. Methods 35 10/801 S, 8020 and 8260/82608. The analyses were performed and a"normal"ten-day turnaround (see 'fables 2 and 3). 5.0 SJC/EHD GeoProbe Data Review S.ICIEHD performed a data review of the GeoProbe borings and Wright sent a reap of the proposed groundwater monitoring well locations; an interim report was not prepared. Once these locations were reviewed and approved by EHD, then the four monitoring wells were installed. 6.0 Field Methods—Drillingand Sampling Monitoring Well Exploratory Borings Four (4) exploratory borings were drilled at approved PHS/ET.4D locations following review of the Limited Phase 11 Investigation data. Drilling and well installation permits were secured from the S.1C/EHD, and an underground utility clearance was completed prior to doing the fieldwork. A site safety plan and traffic control plan was prepared for the site work. The boreholes were drilled with a truck-mounted hollow-stem auger rig. All drilling equipment and sampling tools were cleaned prior to arriving, and before leaving the site. The decontamination process used a tri-phosphate soap to wash the soil sampler between each sample run and each borehole. Augers and drill rods were decontaminated in similar fashion between each borehole using a pressure washer as needed to remove soiVsediment adhering to the augers, rods and drill bits. The hollow-stem augers were advanced and discrete soil samples collected at Five-foot intervals of depth from each borehole_ The augers and drill rod were advanced to the desired sampling depth interval, and a drive split spoon sampler driver ahead of the drill bit For collecting soil samples. The boreholes were logged at five-foot intervals using the Unified Soil Classification System. under the supervision of a professional geologist. Additional lithologic information was collected as needed to describe the subsurface geology. The soil samples were collected at rive- foot intervals, and at intervals of obvious contamination and at stratigraphic features of interest if needed at the discretion of the geologist. Soil samples were field screened with a portable photoionization detector (PFD) for fuel hydrocarbons vapor and staining. Samples showing elevated PID readings were selected for chemical analysis. Upon completion of the borehole drilling and collection of soil samples, the four boreholes were converted to groundwater monitoring wells using the procedures discussed below. Page 4 of 14