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Alk FILE NO. 20-3978-01.WR6 in K L E I N F E L D E R FEBRUARY 24, 1997 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 is reportedly the aquifer tapped by the factory water supply wells. Water level information was also obtained from the Schmidt groundwater reports. In November 1992, depth to groundwater in monitoring wells installed at the site ranged from 20 to 27 feet below grade. The direction of groundwater flow was to the west-northwest, with a gradient of 13 feet/mile. 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. Mr. Donald Schuder of the California Department of Water Resources was contacted for information regarding on site wells. Available well logs were searched for records of wells at the Spreckels site. Copies of the geologic logs for the four monitoring wells installed on site by Ken Schmidt were located. Copies of these logs were not made because they are included in the copy of the monitoring well installation report provided by Spreckels Development. Mr. Schuder was unable to locate additional well logs for the site. Mr. Schuder indicated that this does not mean that no water wells are located on the property, only that he could not locate copies of well logs. Review of the 1985 and 1993 Ken Schmidt reports indicates that five water supply wells (designated 2A, 4, 5, 6A and 7), one livestock well and one domestic well are located on site. Locations of these wells are shown in Plate 2. 20-3978-01.WR61207RE074.do Page 4 of 17 01997, Kleinfelder,1w.