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organic compounds in accordance with EPA Methods 8015M (Simulated Distillation), and 8260 VOCs; and Ii. Prepared a report of findings for the subject property, including conclusions based on the analyses of the samples, and an opinion of the potential for environmental ' contamination of the site with recommendations. GEOLOGY AND HYDROGEOLOGY Stockton is located in the eastern portion of the Great Valley geomorphic province of California. The valley is a nearly flat lying, elongate trough trending northwest and ' southeast for approximately 450 miles. The valley is bordered by the igneous Sierra Nevada to the east and the sedimentary and metamorphic Coast Ranges to the west. The surficial and upper several hundred feet of subsurface sedimentary layers consist of a great thickness of predominantly unconsolidated alluvial and flooplain deposits (dominantly sand, silt and clay), Quaternary in age, which were derived from the predominantly granitic mountains of the Sierra Nevada. Beneath the upper sedimentary deposits lie a thick sequence of marine deposits of Mesozoic age. These units are further underlain by a pre- Jurassic complex of igneous and metamorphic basement rock.5 In the vicinity of the subject property,depth to groundwater is approximately 50 to 60 feet bgs with a flow direction to the northeast. GEOPHYSICAL SURVEY Methodology The Geophysical Survey was conducted by Rietman Consultants of Orange, California in the area south of the Wells Fargo Bank building. The geophysical methodology consisted of GPR, EM, and Mag. Continuous GPR and EM data were collected over the survey area on a five-foot grid consisting of north-south and east-west trending lines. The GPR system provides a record of changes in subsurface soils electrical properties caused by buried objects, changes in soils types, or fluids. The EM profile system provides audio and visual signals over metallic targets. Results of Geophysical Investigation ' Interpretation of the anomalies indicated several linear trends that could be either active utilities which serve the bank building, or irrigation lines in planter areas. They are generally buried two to four feet bgs. The complete geophysical report is included as ' Appendix A. Based on the results of the geophysical survey, there is a low potential that a UST or Zn associated structures are currently present beneath the subject site. 5 Advanced GeoEnvironmental, Inc., Corrective Action Plan, March 1996. 5 197046a - Stockton