Landfill sites have been an under discussion for a number of years. While the importance is paramount, the emphasis has been on recycling waste.
That being said the importance of constructing correctly and using the right materials is critical as the monitoring and checking is under increased scrutiny by our EPA.
Historically the containment layer utilised some form of natural clay resources, but more often than not these materials are not available or require treating beforehand. The alternative is using a clay substitute layer called a GCL (Geosynthetic Clay Liner). This self-healing technology is reliable form of containment but can be susceptible to certain conditions.
To ensure effective containment generally a secondary containment layer comprising of a HDPE liner is put in place. A major factor in maximising the performance of the HDPE liner is the use of a robust geotextile protection layer. This geotextile must be robust enough to provide protection from puncture and ensure that the HDPE liner does not get damaged during construction and placement of the drainage aggregate.
The final act of closing a landfill site is generally poorly controlled and varies dramatically from state to state. However if closed correctly using appropriate Gas Venting and drainage composites, the site can be converted into a reliable source of energy and be safe for alternative use.