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EXECUTIVE SUMMARY Raney Geotechnical, Inc. has completed a Preliminary Endangerment Assessment (PEA) of the subject property. The property is located at 4204 though 4208 North Sutter Street, within a mixed agricultural and residential area of Stockton, San Joaquin County, California. The approximate 12.81-acre subject property currently supports five rural residential structures, associated outbuildings, and surrounding landscaping. The property also includes a large wooden barn, a workshop/storage structure, an unoccupied former bunkhouse, and a number of smaller outbuildings. The remainder of the property is planted with orchard trees (mostly walnuts). The subject property has supported rural residential and farming activities (orchards) for more than 100 years. Between October 2005 and September 2006, a number of soil samples have been collected for laboratory analysis at specific locations at the site, including: within the orchard areas: within the area of the wooden barn (Area A) located on the northerly most portion of the property; within the area of the workshop/storage structure (Area B): near a detached garage (Area Q associated with the residence addressed as 4204 North Sutter Street; and, near a former garage/workshop area(Area D). Our environmental investigations have revealed that past use/handling of pesticides has resulted in impairment of surface soils locally on the subject property. Elevated concentrations of lead, arsenic, organochlorine pesticides, and total petroleum hydrocarbons (TPH) as motor oil were detected in surface soils within very localized areas. The concentrations of TPH as motor oil detected within surface soils are considered relatively low, and are not considered a significant health risk. The primary contaminants of concern detected in soil on the subject property are arsenic, lead, and the organochlorine pesticides 4,4'-DDT and dieldrin; the concentrations detected in site soils have been compared to Federal Environmental Protection Agency Preliminary Remediation Goals (EPA-PRGs), California Environmental Protection Agency Human Health Screening Levels (CHHSLs), and site-specific target clean-up levels established by the Department of Toxic Substance Control (DTSC). Based on the elevated concentrations of lead and arsenic, and the organochlorinated pesticides dieldrin and 4,4-DDT found in surface soils at specific locations on the property, and because of the planned redevelopment of the site as a residential subdivision, it would appear that remedial efforts with regulatory agency oversight is warranted. In our opinion, excavation and proper off-site disposal of soils impacted with arsenic, lead, dieldrin, and 4,4'-DDT within Areas A,B, C, and D would be an appropriate remedial response.