2024-06-25_PERMIT FILE - M2024032 (2)

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Materials Handling - Backfilling The pit floor will receive only enough backfill to create final grading for drainage and to establish a growth medium for revegetation. The pit slopes will require backfilling to achieve final reclaimed slopes of at least 3H:1 V (see Exhibit F, Reclamation Plan Map). Sufficient amounts of overburden should be available on-site to achieve complete side slope backfilling. Materials Handling - Grading The 3H:1 V pit side slopes will be graded to transition into the relatively flat pit floor. Grading of the pit floor may leave a subtle rolling topography rather than a completely flat bottom depending on varying depths of the sand and gravel deposit. The variations in topography will not create water catchment areas, but shall be graded to drain freely. The gentle slope of the topography will control water flow and create a variety of microenvironments for vegetation growth. The side slopes will also not be graded smooth, but will contain a low profile ridging pattern that follows the contour. Final grading that leaves this type of ridging pattern helps to capture water for plant growth as well as reduce the velocity of runoff and slope erosion. On these slopes, erosion may present a maintenance issue for the first year or two of revegetation if there are large drenching thunderstorms, but more normal low intensity thunderstorms should not create more than minor filling. Blending of the pit into existing drainage swales will be important to prevent pooling of water in the pit bottom and to avoid creating a steep slope at the pit edge that encourages erosion. The final grading of this transition area will blend the topographic contouring from the pit floor with the undisturbed topography beyond the pit edge (see Exhibit F, Reclamation Plan Map). All backfilling and grading will be done to stabilize the material and control erosion. Final grading and seeding will be done as soon as possible after backfilling, grading, and topsoiling have been completed. There will not be known toxic or hazardous materials in the backfill material. The reclamation will not leave high walls on the property. In addition, there will be no auger holes, excavations, or shafts left on the property. Topsoil and Revegetation The growth medium for revegetation will be a combination of overburden and topsoils. Unfortunately, there is not a large quantity of quality topsoil available at the site. The topsoil is only marginally different from the overburden, with its main distinction being slightly higher in organic matter. Because of its thin and scarce occurrence, true topsoil stripping will likely incorporate some of the underlying silty clay overburden material. Every effort will be made to separate true topsoil stripping, but even with the incorporation of some overburden material, it is not anticipated that large quantities of the topsoil/overburden growth medium will be available for reclamation. Because of its limited availability, the topsoil/overburden growth medium may not be placed evenly over the entire site. The floor of the pit will likely need less growth medium because 5J Pit DRMS 112 Permit Application Page 11