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+5106388404 ACC FNU1F1-)NMFNTRL 655 PBS SUN 28 '99 161:22 Electrical Substation ACC project No. 99.6006-MA0 DD1C Tracy Size, California page 2 3.1 Soil Borings An excavation permit will be obtained from the PHS-EHD before drilling and sampling activities. The locations of the proposed borings will be marked with white paint. Underground Service Alert will be notified at least 48 hours before commencing work. To further evaluate soil conditions, four borings will be drilled using a hydraulically driven GeoprobcP sampling tool equipped with 1.5-inch, inside diameter, clear, acetate liners. One grab groundwater sample, if groundwater is encountered, and requested soil samples will be collected from each sampling location. Proposed boring locations are illustrated on Figure 3. Actual boring locations may vary slightly based on field observations, safety, utilities, or unknown physical constraints. The sampling probe and rods will be prep-leaned prior to use and between sample drives by washing them with a trisodium phosphate and potable water solution, a potable water rinse, and distilled water rinse. Subsurface soil samples will be obtained by drilling to the approximate desired sampling depth, removing the center rod and drilling point,and driving the sampler 24 inches ahead into undisturbed material. In four representative borings, soil samples will be collected to a total depth of approximately 4 to 5 feet bgs. Upon removal from the sampler, each recovered soil sample will he inspected visually and logged. Samples will be selected for analysis, labeled, and stored in a pre- chilled, insulated container to be transported following chain of custody protocol to a state-certified analytical laboratory. Drilling will be performed under the observation of a Registered Geologist, and the subsurface materials in the borings will be identified and logged using visual and manual methods. Soil cuttings will be logged and classified during drilling operations according to the Unified Sol] Classification System. The boring investigation will be conducted in one day. All Soil samples will be analyzed for California Title 22 Mals lead, chromium, arsenic, and cadmium by BPA Method 6010 and 7400 series, fuel fingerprint by EPA Method 8015 Modified, volatile organic compounds(VOCs)by EPA Method 8260, sernivolatile organic compounds by EPA Method 8270, and polyehlorinatedbiphenyls(PCBs)by EPA Method 8080 Modified. The estimated turnaround time for sample results is 10 to 14 days. 11PA quality assuracelquality control Level TV will be used in accordance with the Army Corps of Engineers' request. Following drilling and sample collection,each boring location will be abandoned with neat cement to just below the surface (1 to 2 inches). The surface of each boring location will be completed with concrete, asphalt,or soil to grade to match the surrounding material.