Risk-based performance assessment of Geosynthetic Clay Liners

GCL-s have very good impermeability features thus in many cases their applicability as bottom liners is raised. In this case the GCL-s compatibility with leachate must be discussed. Such assessments for natural clay barriers are widely known and it is proved that when evaluating leachate-liner compatibility the formation, change and thickness of diffuse double-layer must be investigated. Our institution being a leader higher education unit in environmental geotechnics in Hungary has conducted laboratory tests on several brands of GCL-s before their Hungarian application. The tests aimed to evaluate the mineral composition, permeability, contaminant compatibility and retention capacity of GCL-s, and their comparison to the traditional compacted clay liners. The effect of special stressors (e.g. freeze and thaw, bending) on GCL permeability was also tested. A risk based evaluation was conducted to compare and evaluate the health risk effect and its differences when using alternative liner systems.