MSc Aquatic Ecosystem Management

Landfill practice

The increasing amounts of industrial and domestic waste that we produce need to be disposed of safely: waste is generally landfilled in disused quarries, etc, but no longer simply dumped and covered up. The drainage water from wastes can contain pollutant compounds and must not be allowed to leach into the ground to pollute groundwater or leak into streams.
This shows the base of a landfill: the site has been broken up into cells separated by embankments and covered with an impervious liner.
Each cell has a bed of gravel and is drained
The entire site is surrounded by a bund: when filled the surface of the site will be continuous with the bund
The site is surrounded by a ditch or other drainage options to intercept surface runoff.
Parts of the site where landfilling is complete are landscaped with trees
As well as the trees, the surface is dotted with vertical tubes: these are landfill gas collectors. Landfill gas is mainly methane (C4H4). It is produced by bacteria breaking down organic materials under anaerobic conditions
Methane is a greenhouse gas and should not be allowed to escape into the atmosphere; it is also a useful fuel. The gas collectors are connected to a large main pipe
Collecting pipes run from all over the surface.
The gas is piped to a central point where it can be safely burned off or used to run a generator.
Sample bores have been drilled in the ground surrounding the site.
These are monitored regularly to check that no pollutants are leaching out