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MKLEI_NF ELDER Soil samples will be collected continuously at each probe location using a pneumatically driven steel probe at approximately 4 to 5 foot intervals. Soil samples will be obtained by inserting a sample barrel, lined with acetate liners, into the probe. The sample barrel will be lowered to the desired sampling depth and driven into the soil. The desired sample interval will be cut from the sample collection liners and the sample tubes will be removed and sealed with Teflon film and plastic fitting end caps and immediately placed in an iced cooler. The soil samples will also be collected for lithologic classification and qualitative field screening (PID). Lithologic classification will be based on the Unified Soil Classification System (USCS). GROUNDWATER ASSESSMENT Four pushprobe borings will be advanced to a maximum depth of forty feet in and near the footprint area, to assess potential impacts to shallow groundwater. Mr. Spatafore, owner of the property has indicated static water level from onsite wells is present at approximately 20 feet bgs. However, the well construction and drilling observations during well installation of these well/s is unknown at this time. Therefore, it is unknown if confining groundwater conditions exist which may influence this reported static water level. Groundwater elevations have also been known to vary considerably in the western portion of Tracy in proximity to the Altamont Hills. Based on surface topography at the site and nearby areas, and based on Kleinfelder's experience in the general area, it is estimated groundwater flow direction will generally mimic surface topography and will be east by northeast. Please note however that no onsite data is available to confirm this estimated flow direction. If groundwater is not encountered at approximate maximum depths of 40 feet bgs, groundwater sampling will not be performed. However, if field indications of soil contamination is detected at depths greater than 20 feet, it may be necessary to assess deeper subsurface conditions. One of the deeper four pushprobes will be advanced within the footprint in proximity (and the estimated downgradient direction) to the rupture point and in an area where spilled oil accumulated at the surface (based on aerial photographs of the leak area provided by Chevron Pipeline Company). The three perimeter probes will be advanced just outside of the footprint area. Two of the perimeter probes will be advanced in the estimated downgradient direction of the rupture site, and one in the estimated upgradient direction to the rupture site. The deeper pushprobe boring advanced within the footprint area will be advanced using dual tube methodology to reduce the potential for cross contamination of the potential groundwater sample collected beneath the expected contaminant zone ranging from surface to approximately 15 feet bgs.. The dual-tube will be advanced approximately 15 feet beyond the base where indications of soil contamination is noted based on soil discoloration, odor and PID readings. Because the remaining three deeper pushprobe locations will be advanced outside the footprint area it is not anticipated that a dual-tube methodology will be needed at the perimeter locations. If groundwater is encountered during advancement of the four deeper pushprobe locations, a single grab groundwater sample will be collected at each of the four locations. Groundwater samples will be collected using a stainless steel bailer or by positive displacement through polypropylene tubing attached to a stainless steel ball valve. A disposable screened PVC casing 02001PROP.ENV/ST04P118/DH:ss Page 4 of 8 Copyright 2004,Kleinfelder,Inc. March 22,2004