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• Presently, it appears the bulk of subsurface contamination within 60 to 100 feet of the former UST excavation has been significantly reduced, however, contaminants not captured by previous remediation efforts have migrated south towards (and probably beyond) MW-7. SCOPE OF SERVICES The goal of this proposed investigation is to fully characterize the remaining distribution of contaminants in soil and groundwater beneath the former USTs and affected downgradient areas. Data obtained during the investigation will be used to design an insitu chemical oxidation feasibility pilot test that targets contaminated subsurface intervals within the defined plume area. A membrane interface probe (MIP) supplied by Vironex, Inc. (Vironex) will be used to characterize subsurface lithology and contaminant concentrations in soil and groundwater. The general scope of services will include the following: • Obtain drilling permit from the SJCEHD; • Conduct utility clearance; • Acquire access agreements from involved property owners (as necessary); Conduct field investigation using MIP supplied by Vironex; and • Prepare report of findings Pre-Field Activities Geocon will use an existing site-specific Health and Safety Plan to cover the activities proposed at the site. The document will be reviewed and signed by Geocon personnel and subcontractors performing work at the site. Necessary permits will be obtained from the SJCEHD. Review of existing access agreements will be used for MIP locations on private property. If needed, new access agreements will be obtained from present landowners. Prior to conducting subsurface work at the site, Underground Service Alert (USA) will be contacted to delineate subsurface piping near the site with surface markings. In addition, a private utility locator service will be contracted to further identify subsurface utilities located on private parcels located within the proposed investigation area. MIP Field Investigation A MIP will be used as a field-screening tool to identify the vertical and lateral boundaries of the petroleum hydrocarbon plume in the upper water-bearing zone. The upper water-bearing zone beneath the site and surrounding area exists between 25 and 40 feet bgs. The MIP will be used to log subsurface volatile organic compounds (VOCs) and subsurface lithology to approximately 40 feet bgs at each sample location. A truck-mounted Geoprobe 6600 unit will be used for MIP advancement. A PID and FID will be used with a Geoprobe field computer for real-time semi-qualitative / quantitative hydrocarbon detection in subsurface soil and groundwater, and grab groundwater samples will be collected to confirm the presence or absence of TPHg, benzene, toluene, ethylbenzene, xylenes (BTEX), and MTBE. Data obtained during each MIP advancement will be used to identify additional sample locations as the field investigation proceeds. Project No.E8323-06-01 -2- August 23,2007