REV97265 - Laserfiche WebLink

Home Browse Search

EMBANKMENT DESIGN AND CONSTRUCTION SPECIFICATIONS The embankments for the Pyeatt sedimentation ponds have been designed to be less than ten feet in height from the upstream to the crest of the spillway. Embankment sideslopes are designed to be 2H:1V upstream and 3H:IV downstream, while the width of the top of the embankment is fifteen feet. A typical maximum embankment cross section is shown in Figure 2, Typical Sedimentation Pond Embankment Design. Only suitable materials shall be used for the construction of embankments. Soft, organic, frozen, or coal waste materials will not be used. The embank- ments shall be built in a series of compacted layers, 6 to 12 inches thick. Each layer shall be leveled and compacted before the next layer is placed. When compaction and in-place density tests are performed, they shall be con- ducted in accordance with standard and approved methods. Maximum compaction and optimum moisture content shall be determined by laboratory tests in accor- dance with AASHO Standard Method T99-61. Field compaction and moisture con- tent of embankment materials shall be adequate for use as an earthen fill dam. Construction of each sedimentation pond, including excavation and construc- tion of the embankment, shall be certified by a qualified registered profes- sional engineer. The professional engineer shall inspect each pond during construction and forward certification of the constructed pond to the Division within sixty days following construction. Each sediment pond shall have a staff gauge installed a[ the upstream toe of the embankment at the lowest point of the impoundment. The staff gauge shall have the elevation showing 60% of the designed storage capacity marked on it. All ponds with more than 60% of the sediment volume used will have the sedi- ment removed during the next summer season. r 6 Revised 8/86