Every day Southern Water treats 1,400 million litres of wastewater from 1.7 million properties.

This wastewater is a combination of rainfall, water used in factories and domestic wastewater from toilets, baths, kitchen sinks, washing machines and dishwashers.

Used water, once treated, is safely returned to the environment where it once again becomes part of the water cycle.

There are high treatment standards which Southern Water must comply with set by the Environment Agency in line with directives set by the European Union.

In 2006 every beach in Southern water's region met the Bathing Water Directive standards set by the EU on bathing water quality, with 80 per cent good enough to qualify for a Blue Flag Award.

Treatment

In our region wastewater is transported from homes through a network of 21,000 kilometres of sewers and 2,000 pumping stations to one of nearly 400 works where it undergoes a series of treatment processes.

Each works uses different processes, depending on the local environment, to seperate the water from the 'waste' it carries.

Initially the wastewater passes through fine screens to rmove debris such as paper, before being channelled through grit traps.

During Primary Treatment the wastewater passes into large settlement tanks where solid waste settles and is removed as sludge which is then treated before being recycled as a fertiliser. An alternative process uses Spiral Seperators, circular tanks with giant plastic fins, which use less space.

Secondary Treatment includes biological treatment in a filter bed or aeration tank where naturally-occuring micro organisms feed off the nutrients from the wastewater, breaking down and consuming organic pollutants.

During Final Settlement the cleaned wastewater flows into large tanks for further settlement of any remaining fine particles.

In sensitive areas, wastewater receives Tertiary Treatment in the form of filtration, disinfection or nutrient stripping using chemicals or reed beds.

The final clear liquid is recycled back into the environment and on the coastline this is through Long Sea Outfalls several miles from the shore.

For more information on wastewater treatment download our brochure on Recycling Wastewater in the Environment.