This version of the system is carried out by a field crew using a fully portable set of equipment. At landfills, this version 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 geomembrane instalation and the use of heavy plant in the construction process, the walkover survey is considered to be sufficient in many cases.
Di-pole surveys are used for soil-covered membranes while modified techniques (spark test, arc test, water pudlle, water lance) are also available for exposed geomembranes.
BHF Environmental has specialised in electrical leak detection surveys since 1994.
To detect and locate leaks in plastic membranes, the company uses the geco system. This application of geoelectrics is widely used as an effective tool in the process of Construction Quality Assurance in many countries, mostly for landfill applications, water reservoirs, and other lined liquid containments.
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 potential is mapped over the inspected area. Anomalies in electric field indicate the geomembrane damage.