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15 October 2003 AGE-NC Project No. 03-1079 Page 2 of 5 The Modesto, Riverbank and Turlock Lake Formations and overlying Recent alluvium are the principal sources of domestic ground water in the 13,500-square mile San Joaquin Valley Ground Water Basin(Basin 5-22). 2.2. PREVIOUS INVESTIGATION AND REMEDIATION It is our understanding that a 1,000-gallon underground storage tank (UST) containing regular gasoline was removed from the site in February 1991.Two soil samples were collected from beneath the tank and two soil samples were collected from the product line trench; gasoline and ethylene dibromide (EDB) contamination were detected in the tank samples and volatile aromatic hydrocarbons were detected in the tank and one of the line samples. A preliminary site assessment was performed by Geological Audit Services in March 1994; four borings were advanced and sampled near the former UST location; petroleum hydrocarbons were detected in only Boring B 1. Approximately 1,150 cubic yards ofpetroleum hydrocarbon impacted soil were excavated to a depth of approximately 45 feet below surface grade (bsg) from the former UST site in March 1994; soil samples from the excavation sidewalls and bottom were below detection limits for all analytes. The contaminated soil was stockpiled on the site,then moved to a ranch in Escalon. The soil was tested by AGE in April 1995; subsequent bioremediation lowered the contamination to a level that would be accepted by a landfill and the soil was hauled to Forward Landfill in October 1995. 3.0. SCOPE OF WORK During performance of a Phase I Environmental Site Assessment, AGE noted several areas of potential environmental concern on the property,including the existence of four in-ground hydraulic lifts and a waste oil storage shed. Based upon these concerns, AGE is recommending a limited investigation of the areas. AGE proposes to collect soil samples to determine ifpetroleum hydrocarbon-impacted soil is present in the vicinity of the in-ground hydraulic lifts and the waste oil storage area. The preliminary site assessment will include the following tasks: • Permitting and pre-field work activities; • Soil sample collection and analysis; • Report preparation The preliminary site assessment tasks are discussed below. Advanced GeoEnvironmental,Inc.