Short for electrical leak location. A geomembrane insulates, so a voltage applied across it drives current only through holes, and the survey maps where that current flows. Exposed sheet is checked with water puddle, water lance or arc methods, and covered liners with a dipole survey through the soil, which also catches damage done while placing cover. Many sites require it on top of seam testing.
ELL dipole survey found three holes under the drainage stone, all where the dozer turned.
Schedule the dipole survey after cover placement; most holes on a liner job are made by the cover crew, not the seamers.
Also heard as
- electrical leak location
- leak location survey
- dipole survey
Related terms
CQA
Construction quality assurance: independent monitoring and testing that a geosynthetic system was built as designed.
Leak detection layer
Drainage layer between the primary and secondary liners of a double liner that collects and reveals leakage.
Geomembrane
Low-permeability polymer sheet used as a liquid or gas barrier in liners, covers, ponds and tunnels.