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with foil. Sample containers will be decontaminated per DTSC protocol prior to use. One duplicate sample will be collected for each day of sampling. 3.2 Soil& Groundwater Sampling Field work will be completed under the direct supervision of Mr. Mark Slatten, CEG, CHG. PEI proposes to complete up to 28 soil borings at the subject property based on data from the geophysical and soil vapor surveys (and visual observations of other on-site areas of historical industrial use). These borings are generally planned as follows: - Four(4) shallow soil borings along the railroad spur to approximately 4 to 5 feet bgs. - Approximately twenty(20) soil borings to approximately 20 feet bgs. - Four (4) deeper borings to collect groundwater samples to approximately 40 feet bgs or to first groundwater(whichever is encountered first, or as drilling conditions allow). Some borings may be hand-augered the first 5 feet prior to drilling in an attempt to minimize potential interference with subsurface utilities. Concrete coring to allow drilling access may be necessary where thick concrete is encountered. Borings will be completed using a Geoprobe (direct push) rig. Soil samples will be collected at approximately 5-foot intervals (beginning at 5 feet bgs) in each boring, or as may be determined based on on-site field observations, drilling conditions and proximity to potential sources of impact (e.g., current and former operations, as identifiable). Groundwater samples will be collected using disposable bailers from each temporary monitoring well (e.g., slotted PVC) installed within each deep boring. Continuous or interval soil samples will be collected from surface to total depth. Discrete selected soil samples will be collected via appropriate sampling procedures for laboratory analyses based on physical observations, olfactory, visual staining and field monitoring of soil vapor using a photo- ionization meter. Groundwater is assumed to be encountered at 40 to 45 bgs, based on available Geotracker information for the west adjoining LUST site. One boring is planned at the up- gradient (presumed southwest) end of the site, and the remaining three are planned to be located at the down-gradient ends of the site and/or near items identified from the geophysical survey or soil vapor survey. The soil and groundwater samples will be sealed and placed in a cooler for preservation and delivery to the off-site laboratory under standard chain-of-custody methods. This workplan assumes the shallow borings can be performed using Geoprobe-type direct-push equipment; PEI also assumes residual soil cuttings will be minimal from the shallow borings. The field work is planned for completion within three days depending upon drilling conditions (i.e., using a Geoprobe, soil type, etc.) and whether some of the work can be performed concurrently. All borings will be abandoned with bentonite materials or similar and plugged with concrete or asphalt to match the surrounding surface. When completed, the soil boring locations will be abandoned and permanently sealed in accordance with the requirements of the San Joaquin County. Generally, the borings will be Remediation Pilot Study Workplan Pinnacle Environmental,Inc. 248 industrial Drive,Stockton,CA Page 5