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26 September 2005 AGE-NC Project No. 05-1329 Page 2 of 7 The Great Valley has been filled with sediments derived from both marine and continental sources. Thickness of the sedimentary fill ranges from thin veneers along the valley edges to more than 20,000 feet in the south central portion of the valley. The sedimentary formations range in age from Jurassic to Recent,with the older deposits being primarily marine in origin and the younger deposits being primarily continental. Continental-derived sediments were primarily deposited in lacustrine, fluvial,and alluvial environments with sediment sources being the mountain ranges surrounding the valley(Olmsted and Davis, 1961);the site itself is located on unconsolidated and semi-consolidated alluvium, lake, playa and terrace deposits of Quaternary age (California Division of Mines and Geology, 1981).Rocks composing the basement complex of the Province have not been completely defined but are believed to be metamorphic and igneous in origin. 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). This basin is drained primarily by the San Joaquin River. The nearest surface water features in the vicinity of the property are the San Joaquin River located approximately 5 miles southwest of the site. Ground water at the site is currently encountered at a depth of approximately 19 feet below surface grade (bsg), and has a northwesterly flow direction; based on information from 466 Moffat Boulevard, specifically on-site well MW-8. PREVIOUS SITE ASSESSMENTS AGE personnel performed a site reconnaissance on 29 June 2005 and identified: 1)several areas of auto disassembling; 2) a clarifier/sump and vehicle wash area; 3) an indoor sump; 4) cracked and discolored concrete and asphalt; 5)significant hydrocarbon-staining on both concrete and exposed soil; 6) contaminated sites east and west of the property all of which may be items of potential environmental concerns at the site. There is one monitoring well on-site in the northeast portion of the site which is associated with a leaking underground storage tank(LUST)investigation at the property immediately to the east(466 Moffat Boulevard), there are also multiple wells and one soil boring associated with this investigation near the eastern, northern and southern boundaries of the site. There is one soil boring on-site in the far western portion of the site which is associated with a LUST investigation at the property immediately to the west(3 92 Moffat Boulevard),there are also multiple wells and soil borings associated with this investigation near the western, northern and southern boundaries of the site. Advanced GeoEnvironmental,Inc