ABSTRACT
The data provided by the operators and the on-site investigations clearly showed that incrustation processes occurred at most of the landfill sites and that, together with insufficient drainage of the landfill body, they are the biggest problem for the long-term efficiency of the drainage system. The results of the field investigations can be summarised as follows: Parallel to the investigation of the landfill sites, laboratory experiments were conducted with the aim of simulating the incrustation process. Dismantling the columns which had been subjected to lightly-loaded leachate showed the compost to be locally consolidated and extensively interspersed with a fine tar-like material. A long-term functioning drainage system is just as important for protecting surface water and groundwater as the lining system of a landfill and additionally necessary for ensuring landfill stability. Water discharge from the slope of the landfill was reported for about 40% of the sites.
