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01 July 2016 AGE Project No. 15-3403 Page 6 of 12 6.0. GROUNDWATER INFORMATION - REGIONAL HYDROGEOLOGY The Geologic Map of California, published in 1966 by the California Department of Conservation Division of Mines and Geology, shows the site area within the Great Valley Syncline (GVS), a large, elongate, northwest trending structural trough. The GVS is subdivided into two major divisions designated the Sacramento and San Joaquin Valleys, which have been filled to the present elevation with thick sequences of sediment ranging in age from Jurassic to present day, creating a nearly flat-lying alluvial plain extending from the Tehachapi Mountains in the south to the Klamath Mountains in the north. The western and eastern boundaries of this province are comprised of the California Coast Range and the Sierra Nevada, respectively. Geologically, the area around the subject property generally consists of Holocene-aged flood-basin deposits of clay, silt, and sand. Miocene to Holocene age-units are located in the surrounding area. These deposits are heterogeneous mix of generally poorly sorted clay, silt, sand, and gravel with some beds of claystone, siltstone, sandstone, and conglomerate (Page, 1986). Most of the fresh ground water in the Central Valley is contained in the post- Eocene-aged continental rocks and deposits and in the Holocene-aged river deposits consisting of gravel, sand, silt, and minor amounts of clay. In general, these geologic materials comprise a major widespread aquifer extending hundreds of feet deep and occasionally containing individual confining layers. The Modesto, Riverbank, Turlock Lake Formations and overlying recent alluvium are the principal source of domestic ground water in the 13,500-square mile San Joaquin Valley Ground Water Basin (Basin 5-22). This basin is drained primarily by the San Joaquin River, which is approximately 15 miles north of the subject property. The nearest surface water features in the vicinity of the property is the San Joaquin River, located approximately 8,500 feet northeast of the site. 6.1 . GROUNDWATER DESCRIPTION FOR THE GENERAL AREA The San Joaquin County Flood Control and Water Conservation District's Lines of Equal Depth to Groundwater 2012 Fall indicates the depth to groundwater is 10 feet or less. It is inferred from the map titled Lines of Equal Elevation of Groundwater Fall 2012, also published by the FCD&WCD, local groundwater flow is northeasterly towards the San Joaquin River beneath the subject property. Groundwater flow direction locally appears to be north, in the direction of the San Joaquin R ive r. Groundwater was not encountered in the 48-inch percolation test hole on 30 June 2016. Based upon a review of well permit records at EHD by an AGE representative, the total depth of domestic water wells for the surrounding area was reported to be between 30- feet to 100-feet bsg. Advanced GeoEnvironmental,Inc.