Usually a geonet or drainage geocomposite, it carries any liquid that gets past the primary liner to a sump where it is pumped and measured. Flow is compared with an action leakage rate set for the facility, and going over it triggers an investigation. It is standard in hazardous waste landfills, leachate ponds and many mining solution ponds.
Leak detection layer sump is showing flow after the storm, so either we have a hole or it's construction water.
Also heard as
- LDS
- leak detection system
- secondary collection layer
Related terms
Geonet
Net of extruded polyethylene ribs that forms a thin, high-flow drainage layer within its own plane.
Geocomposite
Product that combines two or more geosynthetics, most often a geonet core with geotextile bonded on one or both sides.
Composite liner
Barrier made of a geomembrane in direct contact with a low-permeability soil or GCL layer beneath it.
ELL
Electrical leak location: surveys that find holes in an installed geomembrane by tracing current through them.