Page 393 - Materials Chemistry, Second Edition

CAT3525_C10.qxd 1/31/2005 12:00 PM Page 364
364 Waste Management Practices: Municipal, Hazardous, and Industrial
First Layer:
● Enter 2 for the first layer type, specifying a leachate recovery layer
● Press <Enter> to specify layer thickness and enter 24 in.
● Press F6 to find the default soil data provided by the HELP program
● Scroll down to Municipal Waste (900pcy) and press <Enter>. This will add the default
data to your table
● Next scroll over (press <Enter>) and enter a value of 0.5 for the initial moisture (vol/vol),
this number must be larger than the specified wilting point
● Press <Enter> to begin adding the second layer

Second Layer:
● Enter 4 for the second layer type, a geomembrane liner
● Enter a layer thickness of 1.0 in.
● Enter 15 for the soil texture number, this denotes a Bentonite mat
● Again scroll over and enter 0.4 for the initial soil moisture

Third Layer:
● This layer will be the same as the first layer, so enter the same information that you used
in Layer 1 above.

Fourth Layer:
● This layer will be the same as the second layer, enter the same numbers from Layer 2
above, the geomembrane liner

Fifth Layer:
● For this last layer, enter a value of 3 for the layer type to denote a layer of relatively
impermeable soil
● Make the layer thickness 48 in.
● Put a soil texture number of 15, a clay soil abbreviated C in the F2 Table
● Add a initial soil moisture value of 0.4 vol/vol
● Press Page Down to continue to the next screen for further data entry
● You will see that your layer type and saturated hydrologic conductivities are already
specified
● Press Enter twice until your cursor is in the “drainage length” cell and type 50 ft for each
different layer (use down arrow to move through the layers)
● Enter a 2% drainage slope for all the layers
● Next enter 95% for the leachate recirculation value for all the layers
● Enter 1 into the “recirculate to layer” cells for each layer and leave the “subsurface
inflow” cells blank for all layers
● Press Page Down to go to the next screen

For geomembrane liners only (type 4)
● Enter 4 for the “geomembrane pinhole density” and 0 for the “geomembrane installation
defects” cells
● Enter 3 for a “geomembrane quality” of Good, a value that assumes good field installa-
tion with well prepared, smooth soil surface and geomembrane wrinkle control to
ensure good contact between the geomembrane and the surrounding soil that limits
drainage rate