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Additional Site Assessment Work Plan OCAMPO PROPERTY (former) 821 South Wilson Way, Stockton, California 1.0. INTRODUCTION At the request of Mr. Victor Aranda,Advanced GeoEnvironmental, Inc. (AGE) has prepared the enclosed work plan for the property at 821 South Wilson Way,Stockton,California(site).The work plan was prepared as required by the San Joaquin County Environmental Health Department(EHD) by letter dated 25 March 2005,to continue delineation of the lateral and vertical extent of petroleum hydrocarbon-impact to ground water at the site. A copy of the EHD directive letter is included in Appendix A. This work plan provides a description of the scope of work and procedures to be used for CPT(Cone Penetrometer Testing) soil boring advancement, ground water sample collection and analysis, and boring abandonment.The plan was prepared in accordance with California Regional Water Quality Control Board-Central Valley Region(RWQCB) guidelines for the investigation of underground storage tank(UST) sites. To date a total seven soil borings and three monitoring wells have been installed at the site, the deepest borings extend to 55 feet below surface grade (bsg). The primary contaminates of concern (COCs) at this site are benzene, 1,2-dichloroethane (1,2-DCA) and total petroleum hydrocarbons quantified as gasoline(TPH-g). The lateral extent of hydrocarbon-impacted shallow ground water has only been defined toward the north and soil has been laterally defined in all directions except immediately to the east of the former UST area. Based on this information soil needs definition vertically at the source area and possibly laterally toward the east of the former UST area. The ground water needs definition laterally toward the south,east and west of the former UST area and vertically near source area. The roadway east of the site is not generally laterally accessible for investigation,due to traffic control constraints according to the City of Stockton. The sidewalk and parking lane east of the site are laterally available, yet the parking lane access is vertically limited by subsurface utilities and utility conduits. Based on recent ground water data, the ground water gradient is generally 0.01 to 0.001 foot/foot (ft/ft) moving in a north-north easterly direction. The current ground water aquifer also appears to be semi-confined to some extent;exemplified by soil borings needing to be drilled to below 50 feet bsg before encountering adequate water to sample,and then the water will rise approximately 10 feet up the boring to the static level of approximately 43 feet bsg.Additional site background information is included in Appendix B. The location of the site is illustrated on Figure 1 and a plan of the site is illustrated on Figure 2. Advanced GeoEnvironmentai,Inc.