Leachateis the liquid that drains or ‘leaches’ from a landfill; it varies widely in composition regarding the age of the landfill and the type of waste that it contains. It usually contains both dissolved and suspended material.
In fact the term “leachate” is so often applied to landfill leachate, both within the waste management industry and outside, that it is easy to forget that leachate is the term used for any liquid produced by the action of “leaching” which occurs when water percolates through any permeable material.
No matter how hard landfill designers and operators try to avoid generating waste, through waste reduction, re-use, recycling, composting and many other methods of waste pre-treatment prior to landfilling, landfilling will continue, and thus leachate generation and its safe disposal without causing pollution, is a problem which is here to stay.
Even if all the landfills could be closed, and the creation of new leachate from rainfall falling on open (operational) landfill phase surfaces, could be stopped today, we would still have to manage the leachate from many thousands of existing operational and closed landfill sites, for generations.