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Page 4 Cabral- McAdams Property August 29, 2006 Job No. 1828-092.02 property in late 2005 and early 2006. The results of our near-surface soils investigation indicate that elevated concentrations of organochlorinated pesticides, lead, and arsenic in soils are present within localized areas on the subject property. A Voluntary Clean-up Agreement (VCA)between the State of California Environmental Protection Agency, Department of Toxic Substance Control (DTSC) and Stephen McAdams (property owner representative) has been prepared for environmental oversight of the pesticide-contaminated near surface soils on the property. Our firm has initiated a Preliminary Endangerment Assessment of the pesticide contamination. Remediation of the pesticide contamination is not addressed in this Final Remediation Plan. To evaluate subsurface soil conditions within the former underground storage tank area, our firm directed the advancing of a number of direct-push borings (Borings B1 through B7); the results of the tank area investigation were presented in a Subsurface Investigation and Preliminary Remediation Plan dated April 28, 2006.2 The borings were advanced to depths ranging from 20 to 40 feet below ground surfaces within the vicinity and peripheral to the area of the former underground storage tank. The results of the laboratory analyses of soils from Boring B2 showed Total Petroleum Hydrocarbon(TPH) as gasoline was identified in the samples collected from depths of 15 and 20 feet at concentrations of 4,300 milligrams per kilogram (mg/kg) and 2,100 mg/kg, respectively. Analysis of a soil sample collected from Boring B3 at the 25-foot interval revealed a concentration of 0.5 mg/kg TPH as gasoline. Petroleum hydrocarbon was not detected in any of the remaining soil samples collected from the seven borings. The oxygenate methyl tert-butyl ether (MTBE) was not detected in any of the samples analyzed from Borings Bl or B2. The results of the laboratory testing are summarized on the attached Table I— Summary of Soil Data. EXTENT OF CONTAMINATION/REMEDIAL EXCAVATION AREA The sampling data presented in the referenced Subsurface Investigation and Preliminary Remediation Plan report indicate that lateral extent pf petroleum hydrocarbon impairment to subsurface soils is very limited and confined to the immediate vicinity of the former underground tank. The data suggest that contaminated"extend vertically to a depth of at least 25 feet. The data from Boring B2 suggest that soils within the upper 10 feet of the excavation area are not contaminated; however, it should be noted that some uncertainty exists regarding the extent of subsurface contamination. It is possible that impacted materials are present beyond the estimated limits. For the purpose of this workplan, the lateral extent of the contamination is an area of approximately 225 square feet (15 feet-by-15 feet); the estimated lateral limits of the area to be excavated are shown on Plate 2. 2 Raney Geotechnical,Inc.;"Subsurface Investigation and Preliminary Remediation Plan,Area of Former Underground Storage Tank, Cabral-McAdams Property, APN 115-230-06, 4204 North Sutter Street, Stockton, California"; April 28, 2006; Raney Reference No. 1828-092.01.