Energy capture or other recovery
Fourth level of the waste hierarchy – other recovery or landfill alternatives
Recovery is another waste management term that can cause confusion. In respect of waste disposal operations, recovery is a very carefully defined term. It means any process or operation where waste is used instead of raw materials. Therefore recycling and some preparing for reuse operations can be, correctly, seen as recovery. Accordingly, other recovery must be operations that are not recycling or preparing for reuse or disposal.
Other recovery is therefore an alternative to landfill and, generally, allows energy contained in waste to be freed up for use. In practice, this takes place in a number of ways including:
- Anaerobic digestion – where the material produced does not meet recycling standards;
- Landspreading of waste that improves or fertilises the soil;
- Backfilling – using waste stone to infill old quarries for example;
- Energy recovery by incineration, pyrolysis or gasification – so called ‘energy from waste’ operations. These operations require highly technical analysis to determine the best environmental outcome.
Although most prevalent in the case of incineration, pyrolysis and gasification, deciding that a particular waste operation is ‘other recovery’ is a complex business and it is very important that the correct determination is made. There is a lot of legal argument around what does and does not constitute ‘other recovery’ and businesses considering this route for their waste should take specialist advice from waste management organisations.