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The GECO system - geoelectrical detection and location of leaks in plastic geomembranes

With our GECO System the locating of any perforating damage to the geomembrane is rapid, accurate and cost effective. The system utilises the insulating properties of geomembranes. An electric current is applied across the protective layer placed over the membrane. Subsequently, the electric potental is mapped over the inspected area. Anomalies in electric field indicate the liner damage.

A - Standard Walkover Survey

This application of the system is used after completion of emplacement of the protective liner covering, prior to the tipping of waste. As the major cause of liner damage results from the use of heavy plant in the construction process, the walkover survey is considered to be sufficient in many cases. This application is carried out by a field crew with a portable set of equipment and does not generally require any third party assistance.

B -  Long Term Leak Location Monitoring

The standard walkover survey can only detect the perforating damage prior to the tipping of waste. However, it may not be sufficient to ensure the long term integrity of the geomembrane. Especially at the early stages of landfilling the tipping of waste can adversely affect geomembrane integrity. Also, some hidden defects (e.g. on extrusion welds) can pass all tests but fail at a later date. The permanently installed GECO system will detect this damage at the stage when the geomembrane is perforated.

The system consists of a network of sensing electrodes placed under the membrane and connected via cables to a monitoring panel at the periphery of the surveyed area. The installation is fast and simple and does not require any changes in the landfill design. The GECO system can monitor either a single or a double plastic liner system.

Over the last 10 years, both walkover leak location surveys and long term monitoring systems became generally accepted methods of checking the integrity of geomembranes. BHF environmental is one of the very few companies having extensive experience in both of these methods