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State Reg. <br />decrease the infiltration of precipitation into the soil and will increase • <br />surface wafer runoff. <br />The replaced topsoil will initially hove lower infiltration rates due to a <br />temporary loss of structure (Gee, et. ol., 1976 and Lusby and Toy, <br />1976). Infiltration and permeability will increase from reclamation <br />year I to year 5 as the vegetation density increases. As the vegetation <br />density increases, surface litter accumulates more rapidly reducing <br />raindrop impact, and surface soil detachment. Roots also penetrate to <br />deeper depths creating additional passageways for percolating water, <br />especially across the topsoil spoil interface. Root penetration and the <br />resultant organic matter accumulation help to develop better soil struc- <br />ture. Structural development is also enhanced by numerous freeze-thaw <br />and wet-dry cycles (Schafer, 1980). Reestablishment of soil structure <br />will allow infiltration and permeability rates to approach and possibly <br />exceed premine rates after 4 to 5 years. Postmine spoil permeability <br />rates may be higher than premine sandstone due to increased volume of • <br />fractures. This 5 year root and structure forming process is further de- <br />scribed in mine soil studies completed by Schafer et. al. (1979 and 1980). <br />The bulk of this infiltration will occur during snowmelt. Lysimeters <br />established on reclaimed spoil produced water only during the spring <br />thaw. During the rest of the year, most of the precipitation will be lost <br />to runoff or to evapotranspiration. <br />Severson and Gough (1981) characterized the Seneca II spoil to contain <br />I) 30% loamy materials 2mm; 2) 50% sandstone and shale fragments <br />2 mm to 25.4 mm; and 3) 20% sandstone and shale fragments 25.4 mm. <br />The mean particle size percentages for 77 crushed (to pass a // 10 - 2mm <br />sieve) spoil samples was 39% sand, 44% silt, and 17% clay. In general, <br />permeabilities in the spoil are greatly increased as indicated by raw data <br />supplied by the USGS for a concrete lysimeter shown in Exhibit 7-2. <br />Permeabilities are expected to be higher still along the mine floor due to <br />accumulation of large spoil fragments by the dragline method of spoil • <br />placement. Wells established in the reclaimed spoil indicate that only <br />the toe of the spoil is saturated. It is anticipated that with time, tl~e <br />7-52 <br />Revised 5/27/81 <br />