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moderately-deep to very-deep, and drainage ranges from partially drained to moderately well-drained on the
<br /> majority of these soils. The water table is relatively high(City of Manteca 2003a).
<br /> Identification of soil types and their distribution was accomplished primarily through a review of maps provided
<br /> by the U.S. Soil Conservation Service(now called the Natural Resources Conservation Service [NRCS]). Exhibit
<br /> 4.7-1 provides a detailed map of the surficial soils in the project area. Table 4.7-3 provides a detailed summary of
<br /> the physical and chemical characteristics of each soil type identified from the project area. A discussion of soil
<br /> characteristics is presented below.
<br /> 108 Arents, 0 to 2%slopes—This soil is found in areas on alluvial fans or fan terraces where ripping, cutting, or
<br /> filling has altered the landscape. Included in this unit are small areas of Manteca, Timor, and Bisgani solid and
<br /> medium textured soils that do not have a hardpan and are not saline-sodic. They are moderately deep or deep to a
<br /> hardpan or are very deep. The surface layer is grayish brown and brown sandy loam or loam about 10 inches
<br /> thick. The upper 30 inches of the underlying material is mottled loam and clay loam, and the next 10 inches is a
<br /> cemented hardpan. The lower part to a depth of 60 inches is stratified loamy sand and sandy loam. The soils are
<br /> saline-sodic throughout. These soils are somewhat poorly drained and nearly level. Permeability is moderate or
<br /> moderately slow. Runoff is slow, and the hazard of water erosion is slight. The soils are subject to rare flooding.
<br /> This soil type has a low shrink-swell potential. Most areas are used for irrigated crops or pasture, and this unit
<br /> may provide wetland functions and values. Limitations include a high water table.
<br /> 109 Bisgani loamy course sand, 0 to 2%slopes—This soil is found on low alluvial fans and formed in alluvium
<br /> derived from granite rock sources. The soil is very deep and is poorly drained. The surface layer is gray loamy
<br /> course sand about 11 inches thick. The underlying material to about 60 inches is mottled loamy course sand. In
<br /> some areas,the surface layer is loamy sand. Included in the unit are small areas of Grangville,Manteca, and
<br /> Veritas soils. Permeability is rapid in this soil. Runoff is very slow, and the hazard of water erosion is slight. The
<br /> hazard of soil blowing is severe. This soil type has a low shrink-swell potential.Most areas are used for irrigated
<br /> crops. A few areas are used as irrigated pasture or for homesite development. If used for homesite development,
<br /> the main limitations are the high water table and the rapid permeability.
<br /> 141 Delhi Fine Sand, 0 to 5%slopes—This soil is very deep, somewhat excessively drained,nearly level soil is
<br /> on dunes. It formed in wind-modified alluvium derived from granite rock sources. The surface layer is typically
<br /> fine sand about 10 inches thick. The underlying material to a depth of about 60 inches is fine sand. In some areas
<br /> the surface layer is loamy sand or loamy course sand. Included in the unit are small areas of Tinnin and Veritas
<br /> soils. Permeability is rapid,runoff is slow, and the hazard of water erosion is slight. The hazard of soil blowing is
<br /> very severe. This soil type has a low shrink-swell potential. Most areas are used for irrigated crops,orchards, and
<br /> vineyards, and a few areas are used for homesite development. The main limitation for homesite development is
<br /> the rapid permeability in the substratum.
<br /> 142 Delhi Loamy Sand, 0 to 2%slopes—This soil is found on floodplains,alluvial fans,and terraces,and formed in
<br /> wind modified alluvium derived from granitic rock sources.Delhi loamy sand is a very deep,somewhat excessively
<br /> drained that grades downward from a brown sand,fine sand,loamy fine sand,or loamy sand to a light yellowish-
<br /> brown sand or loamy sand at depths of 70 inches.Runoff is negligible to slow,permeability is rapid,and there is
<br /> only a slight hazard of water erosion.However,the wind erosion hazard is severe. This soil type has a low shrink-
<br /> swell potential.In San Joaquin County,the primary use for Delhi loamy sand is orchards,vineyards,and alfalfa.
<br /> 143 Delhi-Urban Land Complex, 0 to 2%slopes—This nearly level map unit is on dunes, and is 50 percent Delhi
<br /> loamy sand and 35 percent urban land. The soil is very deep and somewhat excessively drained. It formed in
<br /> wind-modified alluvium derived from granitic rock sources. The surface layer is typically loamy sand about 16
<br /> inches thick. The upper 10 inches of the underlying material is loamy sand, and the lower part to a depth of 60
<br /> inches is pale brown sand. Permeability is rapid,runoff is slow, and the hazard of water erosion is slight. The
<br /> hazard of soil blowing is severe. This soil type has a low shrink-swell potential.Most areas of this unit are used
<br /> for urban development, and a few are used for irrigated crops, orchards, or vineyards.
<br /> EDAW Manteca WQCF and Collection System Master Plans EIR
<br /> Geology, Soils,and Seismicity 4.7-6 City of Manteca
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