Performance of a geosynthetic clay liner in a landfill cover after six years in service

Abstract

Six geosynthetic clay liner (GCL) samples were excavated from the cover of a landfill site closed since 2002 in order to analyse if an evolution of the chemical and hydraulic properties of the GCL had occurred after 6 years in service. This verification was motivated by an important increase in leachate production. Results obtained on the GCL show a poor hydraulic behaviour in relation with a low confining stress, cation exchange and the presence of cracks in the bentonite. This evolution can be explained by the thinness of the covering soil and the cationic exchanges. These results are consistent with previous findings in the literature. With the actual properties measured on the sample, an overall water balance was calculated and helps explaining the increased production of leachate as well as extending the results to the entire cover of the site.