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2. STUDY AREA CHARACTERISTICS
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<br />2.2.2 Soils
<br />The Eugene-Springfield metropolitan area includes at least eight major soils series (Figure
<br />2.2.2-1) and numerous individual soil phases1. Because of the large number of soils and
<br />corresponding descriptions, only a brief discussion of the nine soils located within the area
<br />immediately underlying and surrounding major MWMC facilities (i.e., SIWF, BMF, Biocycle
<br />Farm, and WPCF) is provided below. Soils are categorized according to the facility where
<br />they are located and are shown in detail on Figures 2.2.2-2 and 2.2.2-3.
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<br />WPCF
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<br />· Camas. The Camas series consists of very deep, excessively drained soils that formed in
<br /> gravelly and very gravelly coarse textured alluvium of mixed mineralogy. Camas soils
<br /> are on floodplains 50 to 3,000 feet in elevation and have slopes that range from 0 to 5
<br /> percent. They are excessively drained with slow rtmoff and very rapid permeability.
<br /> They are subject to rare or occasional flooding. These soils are used for growing
<br /> cultivated crops and for woodland. Camas soils are usually irrigated. Natural vegetation
<br /> is Oregon ash, Oregon white oak, red alder, rose, blackberries, annual weeds and
<br /> grasses.
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<br />· Newbergfine sandy loam. This deep, somewhat excessively drained soil is on flood-
<br /> plains and bottom lands at elevations of 290 to 850 feet. Slopes are 0 to 3 percent. This
<br /> Newberg soil formed in recent alluvium and has a moderately rapid permeability.
<br /> Runoff is slow, and the hazard of water erosion is slight. The soil is occasionally flooded
<br /> for brief periods from December to March. This unit is used mainly for row crops, hay
<br /> and pasture, small grain, and orchards. It is also used for urban development and
<br /> recreation. The vegetation in areas not cultivated is mainly Douglas-fir, grand fir,
<br /> Oregon white oak, bigleaf maple, black cottonwood, shrubs, and grasses.
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<br />· Newberg-Urban land complex. The Newberg-Urban land complex soils are on flood
<br /> plains at elevation of 300 to 850 feet. Slopes are 0 to 3 percent. It formed in recent silty
<br /> alluvium. The relatively undisturbed Newberg soil is deep and somewhat excessively
<br /> drained with a moderately rapid permeability. Runoff is slow, and the hazard of water
<br /> erosion is slight. The soil is occasionally flooded for brief periods from December to
<br /> March. The native vegetation is mainly Douglas fir, grand fir, Oregon white oak, bigleaf
<br /> maple, black cottonwood, shrubs, forbs, and grasses.
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<br /> The disturbed Newberg soil has been covered by as much as 40 inches of fill material or
<br /> has had as much as 30 inches of the original profile removed by cutting or grading. The
<br /> fill material commonly is from adjacent areas of Newberg, Chehalis, Cloquato, Camas,
<br /> and McBee soils that have been cut or graded. The characteristics of the disturbed areas
<br /> are highly variable. Urban land consists of areas where the soils are largely covered by
<br /> concrete, asphalt, buildings, or other impervious surfaces that obscure or alter the soils
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<br />I Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer or of
<br />the underlying layers, all of the soils in a series have major horizons that are similar in composition, thickness, and
<br />arrangement. Soils of one series can differ in texture of the surface layer or of the underlying layers. They can also differ in
<br />slope, stoniness, salinity, wetness, degree of erosion, and other characteristics that affect their use. On the basis of such
<br />differences, a soil series is divided into soil phases (NRCS, 1977).
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