ARCHIVED REPORTS_1995 - Laserfiche WebLink

Home Browse Search

marm KLEINFELDER properties equal to the average of those obtained from the soil sampling discussed previously. P q The Chapter 15 cap (Run #2) consists of two feet of foundation layer material, one foot of 1x10 cm/sec clay and one foot of vegetative layer. The soils in the foundation and vegetative layers were assumed to have the same properties as the soil in the existing sideslope. The modified Chapter 15 cap (Run #3) differs from the Chapter 15 cap only in that the thickness of the vegetative layer has been increased from 12" to 32". Results Results of the three modeling runs are summarized in Table 1. Modeling run printouts are contained in Appendix E. TABLE I SUMMARY OF HELP MODELING RESULTS AVERAGE ANNUAL TOTALS FOR YEARS 1 THROUGH 20 (INCISES) Run #3 (Modified Parameter Run #1 (Existing) Run #2 (Chapter 15) Chapter 15) Precipitation 14.51 14.51 14.51 Runoff 0.108 1.0 0.110 Evapotranspiration 12.112 10.192 12.157 Percolation from bottom of landfill 1.142 2.039 1.100 Initial Water Storage (Year O) 40.8 41.88 45.28 Final Water Storage (Year 20) 63.82 67.51 68.19 Change in Water Storage 23.02 25.63 22.91 Note: water storage is a measure of the total amount of water in the landfill. Table 1 shows that there is little difference between the existing sideslope cover and the Chapter 15 sideslope cover. The model actually shows that the existing cover performs slightly better than the Chapter 15 cover (change in water storage is less, percolation from bottom of waste is less). Note that even though the runoff from the Chapter 15 cover is ten times more than for the existing cover, the existing cover performs better. The reason for this lies in evapotranspiration (ET). ET is greater for the existing cover because the depth of the File No.20-1008-49 April 6, 1994 Copyright 1994 Kleinfelder,Inc. Page 4 of 5