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. 15 February 2002 AGE-NC Protect No 96-0229 Page 4of12 23 REGIONAL GEOLOGIC SETTING The property is situated within the Great Valley Geomorphic Province of California, a large, elongate, northwest trending, asymmetric structural trough The Great Valley Province has been filled with thick sequences of sediment ranging in age from Jurassic to Recent, creating a nearly flat- lying alluvial plain, extending from the Tehachapi Mountains in the south to the Klamath Mountains In the north The western and eastern boundaries of this province are comprised of the California Coast Range and the Sierra Nevada, respectively Rocks composing the basement complex of the province have not been completely defined but are believed to be metamorphic and igneous in origin The northern and southern portions of the Great Valley Province have been designated the Sacramento and San Joaquin Valleys, respectively Based on the General Soil Map from the San Joaquin County Soil Survey, published by the United States Department of Agriculture Soil Conservation Service in 1992, the site area is within the Jackson-Hallenbeck-Stockton (JHS) association The JHS soils are located within basins, and generally consist of moderate to poorly drained fine textured soils The soils are generally derived from both marine and non-marine sediment, and are generally formed In alluvium denved from • mixed rock sources 2 4 GROUND WATER DEPTH AND GRADIENT The estimated depth to ground water at the site is approximately 30 feet below surface grade (bsg) based on information from Lines of Equal Depth of Water Wells Fall 1999, published by the San Joaquin County Flood Control District and Water Conservation District(SJCFCD) Based on review of a regional ground water elevation map published by the SJCFCD, the prevailing ground water flow direction in central Stockton is generally toward the northeast, although flow directions may be both locally and seasonably variable Based on ground water monitoring data collected at the site on 31 December 2001, depth to ground water at the site was recorded at approximately 30 feet bsg and ground water flow direction was inferred to be flowing towards the northeast at a gradient of 0 001 ft/ft 3.0. SCOPE OF WORK AGE proposes to drill and install seven wells screened through the First Water Zone (located between 20 and 45 feet bsg) one 6-inch diameter ground water extraction well (EW-1) will be screened between 20 feet and 45 feet bsg, three 4-Inch diameter SVE wells (VW-1, VW-2 and VW-3) will be screened between 10 and 30 feet bsg, one 2-inch diameter IAS well (AW-1) will be Advanced GeoEnvironmental,Inc