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season. During the rainy season infiltration raises the water table and during the dry season drawdown by water well users lowers the water table. GeoLogic's 2007 evaluation concluded that based on groundwater elevations measured in 1984; the highest anticipated groundwater elevation is 2 feet below mean sea level in the southwest portion of landfill and 6 feet below mean sea level in the northeastern corner of the landfill. Wells within one mile of the project site are used primarily to supply water for agricultural and domestic purposes. Of the facilities in the surrounding area, the detention and correctional facilities north of Forward both have wells that are used to supply domestic water. The water used for dust control, compaction, and irrigation on the Forward Landfill site is primarily supplied by a well at the entrance. The well was drilled to a depth of approximately 135 feet and groundwater occurs at a depth of approximately 70 feet. The well was likely ® installed before the opening of the landfill, having been previously used for agricultural ■ purposes. It is pumped at a rate of approximately 1,500 gallons per minute at a maximum frequency of approximately eight times per hour. Forward Landfill drilled a water supply well in the northwest corner of the site to irrigate plants used to establish the riparian habitat created adjacent to the realigned North Creek. There are additional wells present on the southwest portion of the property,which are currently used for irrigation. 3.4 Geology/Soils Forward Landfill is located in the central portion of the Great Valley geomorphic province in the region locally referred to as the northern San Joaquin Valley. The Great Valley is an elongated asymmetrical structural trough bounded on the east by the Sierra Nevada and on the west by the Coastal Range. In the northern San Joaquin Valley, nearly 8,000 feet of sediments have accumulated within the basin, including an accumulation of about 5,250 feet of marine clays, silts and sands subsequently overlain by approximately 2,500 feet of unconsolidated terrestrial sediments. The uppermost portion includes the Pleistocene age Victor Formation. In the northern San Joaquin Valley, this unit includes about 100 feet of laterally and vertically discontinuous fine grained clays and silts with interbedded coarser-grained sediments characteristic of meandering fluvial deposition. The geology and hydrogeology of Forward Landfill have been detailed in several reports including CH2M HILL (1992), Beta Associates (1988), EMCON Associates (1972), and GeoLogic Associates (2008). These studies confirm that the geology as well as the hydrogeology of Forward is consistent with regional conditions. The uppermost sediments of the Victor Formation have been divided into three subunits based on lithologic logs for boring and monitoring wells that identified logical groupings of gross lithology and pervasive color distinctions. The upper 28 to 40 feet consist of highly interbedded sandy silt, clayey silt, silt, and clay. Most of these sediments have an oxidized appearance and an orange brown color. Below this subunit is a 25-to 35-foot thick, gray-brown interbedded sand, silty sand, and minor clay subunit. The third subunit occurs to a depth of about 110 feet and is generally light CADocoments mid SetbngsyessicaseesUDesktoffor d LFGrE-Project Dmnption.doc CORNERSTONE 3-3 LEWIS ENGINEERING Easirav aEeaaaB crag F.LLC