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Administrative Draft Environmental Impact Report Gill Medical Center Project 4.9 Geology and Soils The purpose of this section is to disclose and analyze the potential impacts associated with the geology of the Project site and regional vicinity, and to analyze issues such as the potential exposure of people and property to geologic hazards and erosion.Additionally, this section analyzes the projects impacts to known and unknown paleontological resources. This section is based on the following: Stockton General Plan 2035, Stockton General Plan 2035 EIR, Natural Resource Conservation Service (NRCS)web soil survey (NRCS 2020), and the online interactive Fault Map provided by the U.S. geological Survey (USGS).There were no comments received during the NOP scoping process related to this environmental topic. 4.9.1 Environmental Setting 4.9.1.1 Soils The site is located north of the city of Stockton between West Lane and Ham Lane approximately 550 feet north of Eight Mile Road.The majority of the 42.4-acre Project site is level terrain and is currently used for agricultural production and is planted with vineyard. According to the Web Soil Survey(NRCS 2020a), there is one soil unit mapped within the Study Area: (180)Jacktone clay, 0 to 2 percent slopes (Figure 4.6-2).This soil unit contains hydric components (NRCS 2020b). If the unit is used for urban development, the main limitations are high shrink-swell potential, slow permeability, depth to the hardpan, and low strength. Properly designing foundations and footings and diverting runoff away from buildings helps to prevent the structural damage caused by shrinking and swelling. Properly designing buildings can offset the limited ability of the soil to support a load. (Soil Conservation Service 1992). 4.9.1.2 Faults A fault is a fracture in the crust of the earth along which rocks on one side have moved relative to those on the other side. A fault trace is the line on the earth's surface defining the fault. Displacement of the earth's crust along faults releases energy in the form of earthquakes and in some cases in fault creep. Most faults are the result of repeated displacements over a long period of time. Surface rupture occurs when movement on a fault deep within the earth breaks through to the surface. Surface ruptures have been known to extend up to 50 miles with displacements of an inch to 20 feet. Fault rupture almost always follows preexisting faults,which are zones of weakness. Rupture may occur suddenly during an earthquake or slowly in the form of fault creep. Sudden displacements are more damaging to structures because they are accompanied by shaking.The State of California designates faults as active, potentially active, and inactive depending on how recent the movement that can be substantiated for a fault. Table 4.9-1 presents the California fault activity rating system. Geology and Soils 4.9-1 October 2021