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Topsoil, Roadfill, and Reclamation Material Source (ENG--2) <br />This table gives information about the soils as potential sources of topsoil, reclamation material, and roadfill. Normal compaction, minor processing, <br />and other standard construction practices are assumed. <br />• The soils are rated good, fair, or poor as potential sources of topsoil, reclamation material, and roadfill. The features that limit the soils as sources of <br />these materials are specified in the table. Numerical ratings between 0.00 and 1.00 are given after the specified features. These numbers indicate the <br />degree to which the features limit the soils as sources of topsoil, reclamation material, or roadfill. The lower the number, the greater the limitation. <br />Topsoil is used to cover an area so that vegetation can be established and maintained. The upper 40 inches of a soil is evaluated for use as topsoil. <br />Also evaluated is the reclamation potential of the borrow area. The ratings are based on the soil properties that affect plant growth; the ease of <br />excavating, loading, and spreading the material; and reclamation of the borrow area. Toxic substances, soil reaction, and the properties that are <br />inferred from soil texture, such as available water capacity and fertility, affect plant growth. The ease of excavating, loading, and spreading is affected <br />by rock fragments, slope, depth to a water table, soil texture, and thickness of suitable material. Reclamation of the borrow area is affected by slope, <br />depth to a water table, rock fragments, depth to bedrock or a cemented pan, and toxic material. <br />The surface layer of most soils is generally preferred for topsoil because of its organic matter content. Organic matter greatly increases the absorption <br />and retention of moisture and nutrients for plant growth. <br />Reclamation material is used in areas that have been drastically disturbed by surface mining or similar activities. When these areas are reclaimed, <br />layers of soil material or unconsolidated geological material, or both, are replaced in a vertical sequence. The reconstructed soil favors plant growth. <br />The ratings in the table do not apply to quarries and other mined areas that require an offsite source of reconstruction matedal. The ratings are based <br />on the soil properties that affect erosion and stability of the surface and the productive potential of the reconstructed soil. These properties include the <br />content of sodium, salts, and calcium carbonate; reaction; available water capacity; erodibility; texture; content of rock fragments; and content of <br />organic matter and other features that affect fertility. <br />Roadfill is soil material that is excavated in one place and used in road embankments in another place. In this table, the soils are rated as a source of <br />roadfill for low embankments, generally less than 6 feet high and less exacting in design than higher embankments. <br />The ratings are for the whole soil, from the surface to a depth of about 5 feet. It is assumed that soil layers will be mixed when the soil material is <br />excavated and spread. <br />The ratings are based on the amount of suitable material and on soil properties that affect the ease of excavation and the performance of the material <br />after it is in place. The thickness of the suitable material is a major consideration. The ease of excavation is affected by large stones, depth to a water <br />table, and slope. How well the soil performs in place after it has been compacted and drained is determined by its strength (as inferred from the <br />AASHTO classifcation of the sail) and linear extensibility (shrink-swell potential). <br />r1 <br />I~ <br />USDf~ Natural Resources <br />Tabular Data Version: 3 <br />Conservation Service Tabular Data Version Dale: 04/27/2005 <br />Pa_ e 2 <br />3J <br />