Laserfiche WebLink
The following LISLE constants were utilized for the "closed landfill' condition: <br /> R = 20.41 Average annual rainfall value <br /> K = 0.28 Soil erodibility <br /> 3.20 < LS < Dependent upon length gradient <br /> 5.90 <br /> C = 0.05 Based on vegetative material <br /> P = 0.10 Practice factor <br /> For the purpose of the soil loss analysis, the landfill was divided into regions <br /> based upon the average slopes of the final grades and surface drainage <br /> (Drawing Sheets 2 through 7). The "closed landfill' average soil loss for <br /> Stage IA of the Forward Landfill is 0.15 tons/acre/year which is below the two <br /> tons/acre/year allowed by the CIWMB. Over the 30-year post-closure <br /> maintenance period, the average soil loss over the entire Stage IA partial <br /> closure area will be approximately 0.03 inches. The 30-year soil loss <br /> represents 0.1 percent of the total final cover thickness. This analysis <br /> assumes a seventy to eighty percent ground cover of the specified vegetation <br /> 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 <br /> that will reduce the potential for soil erosion due to water and wind. These <br /> features include vegetation and a slope bench system. <br /> The slope bench will be constructed at approximately a 50-foot vertical <br /> interval along the landfill slope. The final slope bench system and a series of <br /> downdrains will reduce the length of travel of run-off on the slope face thus <br /> reducing the potential for erosion rills and gullies. <br /> The landfill surface will be vegetated with native grasses as shown on <br /> Drawing Sheet 9. The vegetation will protect the upper soil layer and <br /> minimize erosion through the vegetation root masses. Table 4 presents the <br /> seed mix. Additional erosion control measures will be utilized including a silt <br /> fence at the toe of slope, wattles (fiber rolls) and silt fences at the inlets as <br /> shown on Drawing Sheet 9 and detailed on Drawing Sheet D-4. <br /> Forward Landfill PFCPCMP 3-13 <br /> Z:\PROJECTS\Allied Waste\Forward\Reference Files Prior JTD\June 05 Stage IA Partial FCPCMP\FL-sec3.doc:6/16/2008 <br />