How we treat wastewater

Most of us would rather not think about what happens to the water we flush down toilets or use in washing machines. This section explains the daily treatment of wastewater.


Every day we treat and recycle 700 million litres of wastewater at our 368 treatment works after it has travelled through our 39,000 kilometres of sewers (that's six times as long as the entire UK motorway network).

Man-made technology and the power of nature are used to make wastewater safe to return to the environment.

One by-product of the process is 'bio-solids' (sewage sludge), which is turned into fertiliser and sold to farmers for use on crops.

We have a series of films that explain this process further.

Wastewater process films