Laserfiche WebLink
<br />EFCI has designed all sedimentation ponds to minimize the potential for <br />short circuiting. All ponds have been designed and constructed so that <br />the primary outlet structures are located as far as passible from pond <br />inlets. Pond outlet structures are also specifically designed to insure <br />adequate retention time and prevent short circuiting. <br />All pond designs for both the Southfield mine and loadout areas have been <br />developed under the supervision of a qualified registered professional <br />engineer. Consistent with applicable regulatory requirements, <br />construction of all ponds has been certified by a Registered Professional <br />Engineer. These pond certifications are included as an appendix in <br />Exhibit 19, Drainage and Sediment Control Plan. <br />In all cases, construction of existing ponds was consistent with <br />regulatory construction requirements. Foundation areas were cleared, <br />topsoil and incorporated vegetative materials were removed, and foundation <br />i areas were graded prior to embankment construction. Embankments were <br />constructed of materials specifically selected to exclude vegetation, <br />roots, frozen soil, coal or other unsuitable materials. These materials <br />were then placed and compacted in a controlled manner in thin horizontally <br />continuous lifts. As previously noted, existing embankments were designed <br />and constructed to provide a minimum of one (1) foot of freeboard between <br />the emergency spillway design flow level and the top of the embankment. <br />Actual embankment construction height was increased in an increment of <br />approximately 5~ to allow for any potential settlement, and upstream and <br />downstream embankment slopes were established at slopes no greater than <br />2H:1V. Upon completion of construction, all embankment slopes as well as <br />exposed basin areas were graded, scarified and seeded to stabilize the <br />slopes, prevent erosion and establish an effective vegetative cover. <br />Specific design parameters, a description of each sedimentation pond and <br />related design calculations are presented in Exhibit 19, Drainage and <br />Sediment Control Plan. In addition, sediment pond locations and <br />configurations are illustrated by the Mine Area Surface and Groundwater <br />r~ <br />U <br />4.05-18 <br />