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Permit M77-424 Amendment 1 <br />Exhibit E <br />Page 4 of 6 <br />buried in place or will be buried in a designated section of the pond cell. <br />Concrete structures included in this work include the settling pond outlet <br />structure, the main pond outlet structure, and the leak detection vault. <br />6. Re radin .Approximately 10 acres of the pond azea (the azea within the security <br />fence) will be graded and contoured using conventional excavation equipment. <br />Areas previously serving as fill for pond construction will be excavated and <br />redistributed to closely match the original topographic contours. An area of the <br />pond will be designated for concrete disposal for the structures mentioned above <br />and the concrete material buried during grading operations. Any topsoil that was <br />placed on the fill azeas during pond construction will be stockpiled prior to re- <br />contouring work. <br />Recontouring work will be conducted with conventional excavation equipment <br />(e.g. bulldozers, scrapers, and motor graders). Recontouring work will focus on <br />blending any steep side cuts associated with the pond into the surrounding <br />topography and redefining any natural swales or knolls. An effort will be made to <br />construct a topographic surface that minimizes an appeazance of previous <br />disturbance and naturally manages stormwater drainage. The final grade is not <br />expected to exceed a slope of 4 foot (horizontal) to I foot (vertical). However, if <br />a slope equal to or steeper than 4 to 1 is necessary to blend surrounding natural <br />topography, special erosion mitigation measures will be implemented. These <br />measures will include construction of bar ditches on longer slopes and installation <br />of erosion matting after revegetation work. <br />Tonsoil Placement. Once grading and re-contouring work is completed, topsoil <br />from the old and new stockpiles (if any) will be placed over the re-contoured soil <br />surface using conventional excavation equipment (e.g. loaders, bulldozers, and <br />motor graders). If available, approximately 6-inches of topsoil will be placed <br />over the subsoils: However, topsoil placement will be conducted such that the <br />available topsoil from the new and old stockpiles will be evenly distributed over <br />the subsoil materials. <br />.Field observations indicate that the natural topsoil in the terrain surrounding the <br />pond does not have anorganic-rich A-horizon. Frequently, topsoil consists of <br />weathered shale, mudstone, and siltstone. It is assumed that topsoil stockpiles <br />consist of similar material and that this material will suffice For revegetation <br />purposes. <br />8. Revegetation. Revegetation of the re-graded/re-contoured surface will include <br />seeding, mulching, and fertilizing. Before seeding, soil surfaces that appear <br />compacted will be scarified or tilled to depth of 6 to 12-inches. Seed application <br />methods will depend on soil conditions and grade. Seed will be applied through <br />the use of a range drill on slopes less than or equal to 3 feet horizontal to 1 foot <br />vertical. For slopes steeper than 3 to 1, broadcast methods will be used. Seed <br />will be covered using mechanical discing or raking methods. <br />