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Previous mining experience has shown overburden swell to be approxi- <br />• mately equivalent to the volume of mined coal. Therefore, grading to <br /> achieve approximate original contours is not a problem. However, where <br />surface stability can be enhanced by surficial treatments such as pitting, <br />r <br />contour furrowing and the like, this will be done. Basic drainage patterns <br />will not be altered. Once again, though, if improvements in sediment and <br />runoff can be achieved by such techniques as water bars, water spreaders, <br />contour furrows, energy dissipators, and so on, these will be used. <br />Roa~d~~e_* annds will not be rP but disturbances <br />appurtenent to these structures will be stabilized and revegetated. <br />Auger areas (pits 6, 7 and S) will also be backfilled and graded. Final <br />~~ <br />slopes will be laid back somewhat less steep than pre-existing slop but ti <br />~~ <br />otherwise final contours will be the same. Outcropping coal will be buried <br />• by at least 9 feet of safe, non-toxic material. The final fill surface will <br />be scarified prior to placement of topsoil. <br />Care will be taken not to compact the top 2 or 3 feet of overburden in <br />order to provide an adequate zone beneath the topsoil allowing water percola- <br />tion and penetration by roots. On sloping areas the graded surface of the <br />overburden will be made irregular in order to help hold the topsoil on the <br />slope. All regraded surfaces will be mechanically loosened (scarified) <br />prior to redistribution of topsoil to insure a stable interface. <br />2.05.4(2)(d) Topsoil Redistribution <br />Table 3 shows available topsoil volumes for each area to be developed. <br />These estimates were made based on information presented in the soils baseline <br />report. All of the soil except unit 103 is suitable for stripping and stock- <br />piling. Unit 103 has a very thin surface horizon, less than 2 inches, under- <br />. lain by clayey or rocky substrata. Considering the abundance of high quality <br />topso7.1, the small areas of unit 103 soil will not be stripped. <br />N-5 <br />8-81 <br />