Comparison Of Hydraulic Conductivity Test Methods for Landfill Clay Liners

Accurately measuring the in situ hydraulic conductivity (permeability) of a clay liner is a major factor in the construction of landfill containment systems. Laboratory and large-scale field test methods are often utilized on test pads constructed prior to placement of the production liner to determine the hydraulic conductivity of the clay. While these test methods provide reliable results, the time required to run the tests can be lengthy. Due to different soil types or construction methods, variations in hydraulic conductivity between borrow source test pads and production clay liner construction can occur and the ability to quickly determine the clay liner permeability in the field is critical. To avoid potential problems, it is important to be able to correlate laboratory and large-scale field test results with more rapid field test methods. These rapid methods can then be used during the production liner installation to provide quick acceptance to the contractor.