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.. Phase I Environmental SitBl ssessment "SO Page 5 Brookland Farms Subdivision GPE Project No. 440.1 March 19, 2004 2.0 SITE DESCRIPTION 2.1 Property Location and Description ` The Property consists of three parcels of agricultural land totaling about 290 acres on the northwest corner of the intersection of Carter and Henry Roads in a ` rural area of east central San Joaquin County, CA (see maps in Appendix A). It is located near latitude 370 53' 12.5" north and longitude 1200 56' 42.0" west as shown on the United States Geological Survey topographic map, Farmington California Quadrangle, California, 7.5-minute series. 2.2 Geologic and Hydrologic Conditions Hydrology Evaluation of the site's hydrologic conditions included a review of the surface soils and topography during site reconnaissance, interviews with the property owner, a review of the San Joaquin County Flood Control & Water Conservation District, Spring 1999 Groundwater Report and a review of the USGS Topographic Map, Farmington CA Quadrangle. Based upon the interviews and the Flood Control District Report it appears that first groundwater lies ` approximately 130-140 feet below ground surface at an elevation of about 10-20 feet above sea level. Regional groundwater gradient direction is to the northwest, generally consistent with the slope of topography. Soils & Geology The geology of this portion of San Joaquin County is characteristic of the west v side of California's Central Valley. The Central Valley is a large northwest/southeast trending asymmetric trough bounded by mostly pre- Tertiary metamorphic, sedimentary and granitic rocks. Depth to basement rock in the Valley ranges from up to at least 6 vertical miles in the southern portions of the Central Valley (the "San Joaquin" Valley) to up to 10 miles in sediment ` thickness in the northern expanse of the valley (the "Sacramento" Valley). In this portion of San Joaquin County, recently (Cenozoic) deposited terrestrial, lacustrine, and marine sediments overly older (pre-Tertiary in age) consolidated ` marine sediments. These older sedimentary units in turn overly pre-Tertiary crystalline basement rocks. (Source: R.W. Page, U.S. Geological Survey Professional Paper 1401- C, Geology of the Fresh Ground-Water Basin of the Central Valley, California, 1986). r The formation of soils in this part of San Joaquin County is a function of the sedimentary transport path from the primary sediment sources. These sediment sources are the Sierra Nevada to the West of Farmington. Generally, the longer the transport path the greater the working of the sediments prior to deposition r 2937 Veneman Ave.,#13240 Geo-Phase Environmental Inc. Phone: (209) 569-0293 Modesto, CA 95356 Fax: (209)569-0295