2008-12-04_PERMIT FILE - C1994082A (14)

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fragmented material that makes placing it in 12 inch layers impossible, the embankment will be constructed in uniform layers not exceeding in thickness the appr oximate average • size of the rock used, but the layers will not exceed 36 inches. Rock will be distributed by blading or dozing in a manner that will ensure proper placement in the embankment, so [hat voids, pockets and bridging will be reduced to a minimum. The final layer will meet the require ments of 4.03.2(3)(d)(iv). Each layer of the embankment will be completed, leveled end compacted before the succeeding layer is placed. Successive layers will be compacted evenly by routing compaction equipment over the entire width of the embankment. This procedure will be continued until no visible horizontal movement of the embankment material is apparent. Embankment layers will be compacted to a minimum of 90 percent of Standard Proctor density or as directed by the engineer to ensure that the embankment is adequate to support the anticipated volume of traffic and weight and speed of vehicles to be used. Materiel will be placed in en embankment only when its moisture content is within acceptable levels to achieve design compaction. Temporary erosion control measures (ditches, berms, straw dikes, silt fence) will be utilized during embankment construction to minimize sedimentation and erosion until permanent control measures can be established. Immediately upon completion, measures will be taken to stabilize all embankments with vegetation cover or other means as approved by the regulatory authority to minimize erosion. Where a vegetation cover is used, consideration shall be given to providing an appropriate growth medium. Drainage. Each access road not within areas disturbed by mining and reclamation activities will be designed, constructed and maintained to have adequate drainage using ditches end culverts to safely convey the peek runoff from a 10-year, 24-hour precipitation event while maintaining a minimum of one foot of freeboard to the top of the road embankment (see Exhibit 13-9 far typitel details of drainage structures). Drainage ditches will be placed et the toe of all cut slopes formed by the construction of haul roads. Peter will be intercepted before reaching a large fi ll and drained safely away in accordance with the requirements of 4.03.1. Water from a fill will be released below the fill through conduits or in adequately lined channels and will not be discharged onto the fill. • 26