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Here you can find an overview of information about urban waste water treatment (or “sewage treatment”). Map and data products are based on reporting under the Urban Waste Water Treatment Directive.

We need to treat sewage to protect human and environmental health. For most European citizens, waste water is collected, transported and then treated at an urban waste water treatment plant to remove harmful components, before the water is returned to nature.

Sewage is composed of the urine, faeces and dirty water we send down sinks, drains and sewers. It can be combined with urban run-off from roads and hard surfaces, and discharges of industrial waste water. Together, this mixture is called 'urban waste water', and it can contain nutrients, organic matter, disease-causing pathogens and micropollutants. Left untreated, this waste water pollutes rivers, lakes, groundwater and seas, while the resources it contains can be lost.

The Urban Waste Water Treatment Directive (UWWTD) 1991 set treatment standards to protect the water environment, by reducing the amounts of nutrients and organic matter being discharged.

Member States report under the UWWTD to EEA every two years, and data and maps are produced from that reporting.

The European Commission published a proposal to revise the UWWTD in 2022.