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r- Field Methods - Exploratory Borings Task 1. F P Four exploratory borings will be drilled at the locations shown on Figure 1. Drilling permits will be secured from SJC EHD, and a subsurface utility clearance will be performed prior to doing the fieldwork. The boreholes will be drilled with GeoProbe truck mounted drilling equipment. All drilling equipment and sampling tools will be cleaned prior to arriving, and before leaving the site. The probe will be advanced collecting continuous and interval soil sampling in each borehole. Soil samples retained for chemical analysis will be cut from the liners at depths of suspected or obvious contaminant presence. Once retrieved and dissembled, the soil filled acetate liner will be removed and the ends will be sealed with Teflon paper or foil and plastic endcaps,labeled,logged onto chain- of-custody forms and placed on crushed ice in a chilled ice chest. The boreholes will be logged using the Unified Soil Classification System under the supervision of a registered geologist. Additional lithologic information will be collected to describe the subsurface geology. Soil samples will be collected for analysis at five-foot intervals, at intervals of obvious { contamination and possibly at stratigraphic features of interest. Reconnaissance soil vapor measurements will be taken with a portable organic vapor Photoionization Detector (PID). Upon completion of the borehole drilling and collection of soil samples, depth to groundwater measurements and water samples, the boreholes will be sealed per the permit requirements by backfilling with cement grout, placed from the ,bottom to top of each borehole with a tremie pipe. { Drill soil cuttings, decontamination and grout water will be labeled and drummed and placed on-site at a client-designated storage location. Task 2. Field Methods—Reconnaissance Groundwater Sampling Each exploratory boring will be sampled. The ground water samples collected from the boreholes will be used for a relatively rapid reconnaissance of the site groundwater contamination. A brief summary of the sampling procedure follows: Each borehole will be advanced into the aquifer and 1 temporarily cased for sampling. Depth to groundwater measurements will be made to the nearest one-one hundredth of one foot, and also checked for the presence of separate phase product. The water entering the borehole will be sampled using a clean haul line and PVC disposable bailer, and carefully poured into the appropriate laboratory.prepared container with minimum cavitation. Each water sample will be labeled,logged onto a chain-of-custody form, and placed in a chilled ice chest for transport to the laboratory. The temporary casings will be removed following sampling. { An estimate of groundwater flow direction (to a arbitrary datum) will be attempted with k measurements from the temporarily cased boreholes and the depth to water levels will be plotted to { estimate the flow direction. Please note that these uncased boreholes may not be open long enough for groundwater levels to equilibrate so the groundwater flow direction will be a rough estimate. Task 3. Chemical Analysis Up to eight soil samples and up to four groundwater samples will be analyzed at a Kiff Analytical, Inc.,a state certified analytical laboratory. Samples will be tested for the following; Total Petroleum Hydrocarbons as Gasoline (TPHG), Total Petroleum Hydrocarbons as Diesel (TPHD), Benzene (B),Toluene(T),Ethylbenzene (E), Xylene (X), and Volatile Organic Compounds (VOC) Methyl- ] tert-butyl-ether (MTBE), and fuel oxygenates tert-Amyl-Methyl-Ether (TAME), Ethyl-tert-Butyl- Ether (ETBE), Di-Isopropyl Ether (DIPS) and tert-Butyl Alcohol (TBE), and 1,2 Dichloroethane (1,2-DCA), 1,2 Dibromoethane (EDB) using EPA Methods 3550, 3510/8015, 5030, 8020 and 503018260B. Page 2 of 3