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Section 816.46 (u) Continued. Ponds A, D, E, F, G, K, and 0 will have embankments of at least 20 feet in height or will have a storage volume of at least 20 acre- feet. As shown on the plans, Pond A has been designed according to the provisions of 30 CFR 77.216 and 816.46. Specifically, the designs provide for the following: emergency spillways to safely pass the 100-year, 24-hour or larger precipitation event; a static safety factor of 1.5; seepage control barriers to control piping or seepage of water along conduits extending through the embankment; and compliance with all applicable criteria, including those of 30 CFR 77.216. Designs and specifications required by Section 780.25 for ponds D, E, F, G, K, and 0 will be submitted on or about October 15, 1979, in accordance with 30 CFR 780.25 (a)(1)(v). For alI sedimentation ponds, the entire embankment, including the surrounding areas disturbed by construction will be stabilized with respect to erosion by a vegetative cover and mulched immediately after the embankment is completed. The active upstream face of the embankment where water will be impounded will be riprapped or otherwise stabilized. Areas in which the vegetation is not success- ful or where rills and gullies develop will be repaired and revege- tated in accordance with Section 816.106. All ponds, regardless of size, will be examined for structural weakness, erosion and other hazardous conditions, and reports and modifications will be made to the regulatory authority, in accor- dance with 30 CFR 77.216-3. It is hereby requested that the regulatory authority, in considerat- ion of the superior design criteria set forth in the plans approve an examination frequency of once per three months for sedimentation pond embankments not meeting the size criteria of 30 CFR 77.216 (a). a All sedimentation ponds, unless otherwise needed or required by State or Federal law, will be completely removed and reclaimed Exhibit Sp 816-48 72/73/99