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Custom Soil Resource Report <br /> Soil Physical Properties <br /> This folder contains a collection of tabular reports that present soil physical properties. <br /> The reports(tables)include all selected map units and components for each map unit. <br /> Soil physical properties are measured or inferred from direct observations in the field <br /> or laboratory. Examples of soil physical properties include percent clay, organic <br /> matter, saturated hydraulic conductivity, available water capacity, and bulk density. <br /> Engineering Properties <br /> This table gives the engineering classifications and the range of engineering <br /> properties for the layers of each soil in the survey area. <br /> Hydrologic soil group is a group of soils having similar runoff potential under similar <br /> storm and cover conditions.The criteria for determining Hydrologic soil group is found <br /> in the National Engineering Handbook, Chapter 7 issued May 2007(http:// <br /> directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17757.wba). <br /> Listing HSGs by soil map unit component and not by soil series is a new concept for <br /> the engineers. Past engineering references contained lists of HSGs by soil series.Soil <br /> series are continually being defined and redefined, and the list of soil series names <br /> changes so frequently as to make the task of maintaining a single national list virtually <br /> impossible. Therefore, the criteria is now used to calculate the HSG using the <br /> component soil properties and no such national series lists will be maintained.All such <br /> references are obsolete and their use should be discontinued. Soil properties that <br /> influence runoff potential are those that influence the minimum rate of infiltration for a <br /> bare soil after prolonged wetting and when not frozen. These properties are depth to <br /> a seasonal high water table, saturated hydraulic conductivity after prolonged wetting, <br /> and depth to a layer with a very slow water transmission rate. Changes in soil <br /> properties caused by land management or climate changes also cause the hydrologic <br /> soil group to change. The influence of ground cover is treated independently. There <br /> are four hydrologic soil groups, A, B, C, and D, and three dual groups, A/D, B/D, and <br /> C/D. In the dual groups, the first letter is for drained areas and the second letter is for <br /> undrained areas. <br /> The four hydrologic soil groups are described in the following paragraphs: <br /> Group A. Soils having a high infiltration rate (low runoff potential)when thoroughly <br /> wet. These consist mainly of deep, well drained to excessively drained sands or <br /> gravelly sands. These soils have a high rate of water transmission. <br /> Group B. Soils having a moderate infiltration rate when thoroughly wet.These consist <br /> chiefly of moderately deep or deep, moderately well drained or well drained soils that <br /> have moderately fine texture to moderately coarse texture. These soils have a <br /> moderate rate of water transmission. <br /> Group C. Soils having a slow infiltration rate when thoroughly wet. These consist <br /> chiefly of soils having a layer that impedes the downward movement of water or soils <br /> of moderately fine texture or fine texture. These soils have a slow rate of water <br /> transmission. <br /> Group D. Soils having a very slow infiltration rate (high runoff potential)when <br /> thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, <br /> soils that have a high water table, soils that have a claypan or clay layer at or near the <br /> 50 <br />