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5.4 Geologic Hazards and Resources <br /> This section evaluates the geologic hazards and resources at the Lodi Energy Center (LEC) <br /> project site. Section 5.4.1 describes the existing environment that could be affected, <br /> including regional and local geology and geologic hazards. Section 5.4.2 identifies potential <br /> environmental effects from project development. Section 5.4.3 discusses potential <br /> cumulative effects. Section 5.4.4 discusses possible mitigation measures.Section 5.4.5 <br /> presents the laws, ordinances,regulations,and standards (LORS) applicable to geologic <br /> hazards and resources. Section 5.4.6 provides agency contacts. Section 5.4.7 describes the <br /> required permits. Section 5.4.8 provides the references used to develop this section. <br /> 5.4.1 Affected Environment <br /> The LEC site is a 4.4-acre parcel off of North Thornton Road on land owned and <br /> incorporated by the City of Lodi southwest of the intersection of Highway 12 and <br /> Interstate 5,at the end of North Cord Road.The site is relatively flat and gently slopes to the <br /> west. <br /> 5.4.1.1 Regional Geology <br /> The project area is situated in the Great Valley Geomorphic Province. The Great Valley and <br /> the adjacent Sierra Nevada to the east form a relatively stable crustal block (Sierran block) <br /> composed of Mesozoic crystalline basement that dips gently to the west.The western edge <br /> of the Sierra Nevada block,beneath the sediments of the Great Valley,may be coincident <br /> with the western margin of the Great Valley (Anderson,1943). <br /> The Great Valley physiographic province separates the Coast Ranges to the west from the <br /> Sierra Nevada to the east. This province is composed of two elongated northwest-to <br /> southeast-trending basins: the Sacramento basin to the northwest and the San Joaquin basin <br /> to the southeast. The present-day basin evolved from a late Jurassic to middle Tertiary <br /> (40-150 million years ago) marine fore-arc basin. In the late Tertiary (25-30 million years <br /> ago), a change in the relative motion between the Pacific and North American plates <br /> resulted in the gradual uplift of the Coast Ranges and the eventual isolation of the basin <br /> from the ocean. More recent Miocene and lower Pliocene sediments were derived from the <br /> neighboring Coast Ranges and the Sierra Nevada. By the late Pliocene (2-3 million years <br /> ago), subaerial depositional conditions prevailed and Sierra Nevada-derived sediments <br /> were deposited in the basins (Olmsted &Davis, 1961). <br /> 5.4.1.2 Local Geology <br /> The project site is in an area of relatively flat topography typical of the Central Valley. The <br /> surficial geology within a 2-mile radius of the site is shown on Figure 5.4-1. The geologic <br /> units that are present within this 2-mile area are described below with details provided by <br /> Preliminary Geologic Map Showing Quaternary Deposits of the Lodi, California Quadrangle, Open <br /> File Report 79-933 (USGS, 1979). Near-surface sediments in the area of the site have been <br /> deposited primarily from the Sacramento,Mokelumne,and San Joaquin river systems. The <br /> LEC project site is on the eastern edge of the Sacramento-San Joaquin River Delta (Delta). <br /> Groundwater at the site has been detected at a depth of approximately 10 feet below ground <br /> surface (Carlton,2008). <br /> SAC/371322/082330011(LEC-5.4-GEOLOGIC HAZARDS AND RESOURCES.DOC) 5.4-1 <br />