In principle, all PEHD membrane sealing systems can be inspected using this method. Typical applications are listed below. As part of the tendering process, ELD will evaluate the technical background conditions that are relevant to monitoring and ensure the optimal preparation of the system for performing a survey.

Landfill base liner

Landfill base liners

There are several phases of preparation of landfill base liners, starting with the positioning of the membrane, until these can be covered with several metres of refuse. These membranes may be damaged during preparation, but can also be inspected and repaired. It is advisable to undertake inspections at regular intervals.

Areas which are already covered and are many meters below the surface and which are therefore no longer readily accessible for repair should nevertheless be inspected if there is any concrete reason to suspect that their integrity could have been impaired, for example as a result of fire.

Basins with covered synthetic liner sheet


For reasons of environmental protection, basins often need to be leakproof, e.g. seepage basins on landfill sites. However, it can also be important to ensure, for example, that valuable water does not escape into the subsoil undetected.

Due to the diversity of basin types, there are also many different possible technical solutions that can be used for monitoring them. Ideally, a detection cable network should be installed when the basin is built. However, if the conditions are favourable, the leak-proofing characteristics of existing basins can be determined even when these are filled.

Erosion at landfill surface liner

Landfill surface liners

Unlike base liners, surface liners are not buried at some point under many metres of waste and instead are usually protected over the course of many years only by a 1-metre thick mineral layer. As a result, there can be uncertainty about the integrity of their leak-proofing characteristics, particularly if the land is subsequently used for other purposes; however, at the same time, repairs are also possible at reasonable cost if the location of any damage can be established.

Internal erosion


In the mining industry, dams are built to create tailings storage facilities.

In the event of undetected damage, internal erosion can occur in the dam, and as a result, dam stability can also be affected at certain points. This risk can be minimised significantly by regular monitoring and repair as and when required, especially during and shortly after construction.