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section. <br />The pre mine water volume required to be stored in Pond 011 is 4.52 acre -ft. The post mine <br />water volume that must be stored in Pond 011 is 9.9 acre -ft. The post mine conditions are the <br />worst case, and therefore are used to determine if Pond 011 is sufficient. As shown by the <br />SEDCAD calculations, Pond 011 has 12.3 acre -ft of capacity at the emergency spillway, and <br />will be able to hold the worst case (pre mine) conditions. <br />The pond design does not meet MSHA Impoundment criteria, as shown below, since it does not <br />have a storage volume of 20 acre -ft and does not have an elevation of 20 feet. <br />30CFR77.216 Water, sediment, or slurry impoundment and impounding structures; general. <br />(a) Plans for the design, construction, and maintenance of structures which impound water, <br />sediment, or slurry shall be required if such an existing or proposed impounding structure can: <br />1. Impound water, sediment, or slurry to an elevation of five feet or more above the upstream <br />toe of the structure and can have a storage volume of 20 acre -feet or more; or <br />2. Impound water, sediment, or slurry to an elevation of 20 feet or more above the upstream <br />toe of the structure; or <br />3. As determined by the District Manager, present a hazard to coal miners. <br />REVISED AUGUST 2009 Attachment 2.05.3(3) -14 -11 <br />