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Materials Handling - Baclfilling <br />A "cut and fill" approach will be used to create side slopes and overburden material will be used <br />as growth medium cover. The pit floor will receive only enough backfill to create final grading <br />for drainage and to establish a growth medium for revegetation. Because of the general lack of <br />overburden and potential depth of the deposit, it will not be possible to achieve side slope <br />reclamation by backfilling with available overburden material. Although the overburden <br />material is generally deep (4 to 6 feet) on the relatively flat pediment surface, the total area for <br />overburden recovery is limited. Preliminary material balance estimates suggest that <br />approximately 150,000 cubic yards of overburden material may be available, but the maximum <br />depth of the pit at possibly 30 to 50 feet and the desired reclamation slopes of 3H:1V could <br />require 150,000 cubic yards or more just for backfilling. In addition to the side slopes, <br />overburden material is also required to cover the pit floor for drainage grading and to establish a <br />growth medium. The result is, 3H:1V side slopes will be created by "cut and fill" of the near <br />vertical mine face and highwalls (see Exhibit F -1, Reclamation Plan Typical Sections). <br />Materials Handling - Grading <br />The 3H:1V pit side slopes will be graded to transition into the relatively flat pit floor. <br />Backfilling and grading of overburden and soil on the pit floor will leave a subtle rolling <br />topography rather than a completely flat bottom. The rolling topography for the pit floor is to be <br />very subtle with relief of less than a couple feet. Although additional overburden will be used if <br />available, only one foot of overburden cover is planned at this time. The rolling topography <br />could also be described as leaving broad and subtle furrows in the final grading. These rough <br />grading elements will be created using overburden and topsoil and should not create water <br />catchment areas, but should be graded to drain freely. The topography is intended to control <br />water flow and create a variety of microenvironments so a wide variety of vegetation <br />assemblages can develop. This form of final grading greatly improves the diversity of wildlife <br />than can live on the area and also encourages some dynamic interaction between different <br />vegetation forms. <br />The side slopes will also not be graded smooth, but will contain a low profile ridging pattern that <br />follows the contour. Final grading that leaves this type of ridging pattern helps to capture water <br />for plant growth as well as reduce the velocity of runoff and slope erosion. On these slopes, <br />erosion may present a maintenance issue for the first year or two of revegetation if there are <br />large, drenching thunderstorms, but more normal low intensity thunderstorms should not create <br />more than minor rilling if the grading ridges are done along the contour. <br />Blending of the pit outlet is important to prevent pooling of water in the pit bottom and to avoid <br />creating a steep slope at the pit edge that encourages erosion. The final grading of this transition <br />area will blend the topographic contouring from the pit floor with the undisturbed topography <br />beyond the pit edge. <br />Topsoiling and Growth Media <br />As is currently the case at the Fountain Pit, the growth medium will be a combination of <br />overburden and topsoils. Unfortunately, there is not a large quantity of quality topsoil available <br />Fountain Pit M- 1982 -155 <br />DRMS 112 Permit Amendment <br />Revised in Response to Adequacy Review Comments Page 12 <br />