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Surface &Subsurface Contamination Report Page 9 Sandhu Property Project No. 522.1 March 9, 2006 2.0 SITE DESCRIPTION 2.1 Property Location and Description The Property consists of a 36.9-acre, approximately triangular-shaped agricultural parcel. It lies inside an area bounded by Highways 132 and 33, and Welty Road, just north of the unincorporated town of Vernalis. In the land survey grid, it is located in the NE 1/4 of Section 34 of T3S R6E, MDB&M as shown on the United States Geological Survey topographic map, Vernalis California Quadrangle, California, 7.5-minute series. 2.2 Geologic and Hydrologic Conditions Soils & Geology The Central valley is notable for thick sedimentary deposits which range in age from recent to Eocene and older and which may extend to depths of more than 20,000 feet. In the Patterson area, the thickness of these sediments is much thinner due to the proximity of the town to the western margin of the valley. Surface soils in the Patterson soil are also derived from the coastal range. j Cretaceous and younger rocks consist principally of marine sediments with some ultramafic and metasedimentary rocks, which are naturally eroded and transported to the east. The erosion products form a series of coalescing alluvial fans on which Patterson is situated. _ According to the soils information contained in the EDR report, the specific on site soil is a type called Vernalis Clay Loam: moderately permeable, clayey soil with silt, and moderate runoff. Hydrology Evaluation of the site's geologic and hydrologic conditions included a review of the surface soils and topography, a review of groundwater monitoring reports for nearby known contamination sites, a review of the USGS Topographic Map, Vernalis Quadrangle and the map Lines of Equal Depth in Water Wells, which is attached to Geology of Fresh Groundwater Basin. Central Dalley. California. USGS Professional Paper 1401-C, 1986. Based on this map the surface of groundwater is estimated to he about 20 below grade and flow in a northeasterly direction. Groundwater monitoring data from two remedial investigations in central Patterson suggest that locally, groundwater lies at about 35 feet below grade and flows in an easterly direction. In much of the Central Valley, the shallow groundwater contains marginally potable water, and generally the only water production wells completed opposite this zone are domestic wells. The shallow aquifer is composed of shallow sand, ., 2937 Veneman Ave.,#13240 Geo-Phase Environmental Inc. Phone: (209) 569-0293 Modesto, CA 95356 Fax: (209) 569-0295