Bentonite cut-off walls: solution for landfill remedial works

Abstract

The application of landfill containment systems such as cut-off walls could be used effectively as one of the remedial solutions limiting environmental hazards caused by such sites. The complexity and weight of problems concerning remediation works of old sanitary landfills having been considered and interdisciplinary engineering and ecological solutions are recommended. This paper discusses threats to the environment emerging from old landfills and polluted areas and presents examples of engineering solutions used for the remediation of the old, large embankment-type Radiowo landfill located in Warsaw, Poland. The principal remediation problem for the Radiowo landfill was protection systems against leachate migration and groundwater pollution. The research included bentonite vertical barrier quality tests involving both laboratory and on-site hydraulic conductivity tests. Furthermore, a quality assessment based on the groundwater flow and transport modelling and an analysis of monitoring records are presented. The output of the research is the proposal of a dual device employing monitoring and numerical modelling processes for the purpose of controlling the self-purification of soil–water environments after the implementation of containment systems on contaminated sites.