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KLEiNFELDER characterized as mixed-use, retail, light commercial industrial, agricultural and residential property. 2.3. GEOLOGY AND HYDROGEOLOGY The site lies within the Great Valley Geomorphic Province of California. The valley is approximately 400 miles long and averages about 50 miles wide, and encompasses approximately 20,000 square miles. The valley has been filled with a thick sequence of marine and non-marine sediments from the late Jurassic to Holocene. The uppermost strata of the Great Valley represent, for the most part, the alluvial, flood, and delta plains of two major rivers (Sacramento and San Joaquin Rivers) and their tributaries. The valley deposits are derived from the Coast Ranges to the west and the Sierra Nevada to the east. Granitic and metamorphic rocks outcrop along the eastern and southeastern flanks of the valley. Marine sedimentary rocks outcrop along most of the western, southwestern, southern, and southeastern flanks; and volcanic rocks and deposits outcrop along the northeastern flanks of the valley. The valley geomorphology includes dissected uplands, low alluvial plains and fans, river flood plains and channels, and overflow lands and lake bottoms. Site specific geologic information was obtained from two documents prepared for Spreckels Sugar by Kenneth D. Schmidt, Groundwater Quality Consultant (Schmidt ' 1985 and Schmidt 1993). The documents are technical reports on groundwater monitoring efforts associated with the wastewater, lime and mud ponds on site. According to Mr. Schmidt, coarse-grained alluvial deposits, primarily fine to medium grained sand, are present to a depth of at least 60 feet below grade. Localized clay strata are also present in the upper 60 feet. Additionally, two major clay layers are present beneath the site at approximate depths of 95 to 141 feet, and 188 to 243 feet. Mr. Schmidt identifies the deeper clay layer (188 to 243 feet) as the Corcoran Clay, a major regional confining bed that occurs along the west side of the San Joaquin Valley. Mr. Schmidt indicates that several major gravel deposits occur at depths of 40 to 65 feet, 110 to 130 feet, and 300 to 340 feet below the site. The deepest gravel layer was reportedly the aquifer tapped by the factory water supply wells at that time. 1 Water level information was also obtained from the Schmidt groundwater reports in addition to numerous Kleinfelder documents. Generally, during the period of the monitoring (1992 to date) the groundwater elevation beneath the project site ranged from approximately 17 to 28 feet above mean sea level. The direction of groundwater flow was predominantly to the west-northwest. Historical groundwater information obtained by Mr. Schmidt indicates that in 1950 depth to groundwater beneath the factory was 10 feet with a direction of groundwater flow to the west. Depth to groundwater in the vicinity of the site has historically ranged from 10 to 26 feet below grade, with groundwater flow directions varying from due west to northwest. 20-3978-03.MN7/ST08R117 2008 Kleinfelder February 1,2008 © Page 3 of 19