Laserfiche WebLink
total final cover thickness. This analysis assumes a seventy to eighty percent <br /> ground cover of the specified vegetation will exist over the post-closure period. <br /> 3.6.3 EROSION CONTROL <br /> The Stage IA partial closure design has two primary erosion control features that <br /> will reduce the potential for soil erosion due to water and wind. These features <br /> include vegetation and a slope bench system. <br /> The slope bench will be constructed at approximately a 50-foot vertical interval <br /> along the landfill slope. The final slope bench system and a series of downdrains <br /> will reduce the length of travel of run-off on the slope face thus reducing the <br /> potential for erosion rills and gullies. <br /> The landfill surface will be vegetated with native grasses as shown on Drawing <br /> Sheet 9. The vegetation will protect the upper soil layer and minimize erosion <br /> through the vegetation root masses. Table 4 presents the seed mix. Additional <br /> erosion control measures will be utilized including a silt fence at the toe of slope, <br /> wattles (fiber rolls) and silt fences at the inlets as shown on Drawing Sheet 9 and <br /> detailed on Drawing Sheet D-4. <br /> 3.7 FRENCH DRAIN LIQUID SEEP COLLECTORS <br /> French Drain Liquid Seep Collectors will be placed in the areas shown on <br /> Drawing Sheet 8. The collectors will consist of a geonet drain placed along the <br /> slope in the area of the seep. As shown in Detail 2 of Drawing Sheet D-3, <br /> approximately 3 feet of final cover soil will be placed on top of the geonet drain. <br /> The geonet will direct liquids by gravity flow to a gravel drain at the toe of the <br /> slope. The gravel drain will be wrapped in a geotextile and may be underlain by <br /> a Flexible Membrane Liner (FML) which would extend approximately 24 inches <br /> up the slope (FML optional). A three-inch perforated high-density polyethylene <br /> (HDPE) pipe will be placed in the gravel drain and will direct liquids to a holding <br /> tank down gradient of the seep. Liquids collected in holding tanks will be <br /> treated as leachate and handled consistent with current procedures. <br /> Forward Landfill PFCPCMP 3-13 <br /> ):\Allied\Forward\2005.0051 Partial Closure\Partial Closure Plan\FL-sec3.doc:6/15/2005 <br />