Geonet drainage layer

A Geonet drainage layer can be chosen if the HELP model shows it to be more effective than sand in controlling leachate production and is comparable in cost. It is assumed that the HELP model predicts a 75 to 80% reduction in leachate production. A Geotextile layer would be laid on either side of the Geonet drain to prevent clogging. A minimum slope of 3% would be provided to meet state requirements. 

U.S. EPA specifies that the minimum detection time for the leachate entering the LDS of an LDCR system is <24 h. Response time calculations are based on velocity in the geonet and/or granular soil drainage layer. Darcy s law is used to calculate flow velocity in the geonet, and a true velocity must be used for granular soil. 

The approach of multilayering of coarse and fine fibres has also been applied for enhanced drainage functionality. One development is a three-layer non-woven geotextile which is claimed to give a better performance than drainage geocomposites with a geonet core. The three-layer non-woven... 

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