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Emergency Remediatio•2480 Tracy Blvd., Tracy, CA. • Page 3 INITIAL INVESTIGATION To verify the presence of components of gasoline in the soil exposed by the excavation and to quantity their concentrations, two soil samples were taken from the area of the foundation excavation at a depth of approximately 8 feet on April 3, 1996. The samples were recovered in the presence of a representative of the San Joaquin County Public Health Services, Division of Environmental Health (SJCPHS) and transported, under chain of custody control, to Chromolab Inc's laboratory in Pleasanton, California which is licensed by the California Environmental Protection Agency. On the same day, a water sample was taken from a sampling port installed in the discharge line from the dewatering system and was also transported to the laboratory under chain-of-custody control, and submitted for analysis to determine the presence and, if present, the concentration of gasoline in the groundwater beneath the site. Both the soil and the groundwater samples will be analyzed for total petroleum hydrocarbons as gasoline, benzene, toluene, ethylbenzene and total xylene isomers. In addition, the water sample will be analyzed for the presence of MTBE, an antioxidant compound that has recently been introduced as an additive to gasoline. As soon as possible following submittal of this plan to the SJCPHS, a drill rig operated by a drilling contractor holding a C57 licence issued by the California Contractors State License Board will be mobilized to the site to obtain additional soil samples from the subsurface. The drill rig will be capable of either push probe sampling or soil boring using a hollow stem auger. Boring locations, which are expected to number between ten and fifteen, will be selected so as to aid an assessment of the extent of the area over which soil beneath the site has been affected by released hydrocarbon fuel and, specifically, to explore the extent, degree and characteristics of contaminated in areas of the property that are contiguous with the former site of the Chevron gas station, which is upgradient of the subject property, so as to confirm that facility as the source of the hydrocarbon contamination that has been found beneath the 2480 Tracy Boulevard property. The soil samples will be obtained from depths between five and nine feet beneath the ground surface for the purpose of evaluating the areal extent of contamination at the depth of the water table. These samples will be analyzed for total petroleum hydrocarbons as gasoline, benzene, toluene, ethylbenzene and total xylene isomers at Chromolab Inc's Pleasanton, California laboratory. Upon completion of sampling, the borings or push probe holes will be sealed, under the oversight of the SJCPHS, with hydrated bentonite or a tremied bentonite and Portland cement grout as appropriate for the diameter and type of boring that will be drilled. A permit for the drilling or push-probe sampling will be obtained from the SJCPHS prior to initiation of the subsurface investigation