Landfill: Surface Water Collection and Removal System (SWCRS)

Landfill capping are typically waterproofed using either a geomembrane or a geosynthetic clay liner (GCL).

Infiltrating rainwater flowing over the liner drastically reduces the coefficient of friction at the soil/membrane interface producing, in addition, overpressures that can certainly promote slippage of the soil layer over the covering system.

TENAX TENDRAIN geocomposites, properly installed on top of the waterproofing layer, shall be selected to reduce the amount of rainwater that might reach the liner interface.

Surface water infiltrating through the cover soil will accumulate above the barrier layer and generate detrimental pore water pressure if it is not properly drained. Excessive head buildup due to inadequate drainage can cause catastrophic failure of the cover, numerous seepage-induced landfill slope failures have been recorded and analyzed to confirm this.

TENAX TENDRAIN geocomposites and TENAX GNT provide the highest flow capacity among any geonet. The long-term in-soil transmissivity of TENAX TENDRAIN is in the order of 6 x 10-3 m2/s at a gradient of 0.1, and 4 x 10-3 m2/s at a gradient of 0.33. Long-term (10,000 hour) testing indicates that TENAX TENDRAIN maintains over 90% of its thickness when exposed to long-term compressive loads.

This retained thickness maintains an open flow channel into which geotextiles are kept from intruding and rain water is free to flow.

Products

TENAX TENDRAIN geocomposite

TENAX GNT geonet