European Union

Overview: urban waste water production and its treatment

Collection and treatment of waste water are key to reducing pressures and risks to human health and the environment, especially to rivers, lakes, and coastal waters. % of Europe’s urban waste waters are collected and treated in line with EU standards.

In , households and certain industries in urban areas generate million p.e. of waste water every day, which is an amount equivalent to around million bathtubs or million m³.

Urban waste water needs to be treated before discharge, in order to avoid pollution to the environment. In countries, urban waste water is treated in plants across the country before it is discharged.

Figure 1
Number of treatment plants by type of treatment

Biological treatment with nitrogen and phosphorus removal

Biological treatment

Primary treatment

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Map view 1
Plants by treatment type

Zoom in to check the treatment plant of your interest (pop up window with detailed information opens when clicking on a point in the map).

Figure 2
Amount of urban waste water which is required to be collected and treated according to the UWWTD

Amount of waste water in million p.e.

Total generated

Collection

Biological treatment

Biological treatment with removal

Sources: Waterbase - UWWTD: Urban Waste Water Treatment Directive – reported data. European Environment Agency (EEA)

What are the targets for urban waste water collection and treatment for all countries?

According to the UWWTD, is required to provide in urban areas:
- Collection of million p.e. of waste water
- Biological treatment to million p.e. of waste water
- Biological treatment with removal to million p.e. of waste water

In addition, for 14.71 million p.e. of urban waste water does not need to apply biological treatment, because this is waste water discharged into coastal areas from smaller urban areas (below 10,000 p.e.). These alternatives are allowed by the legislation, as long as the environment is adequately protected.

This is why the amount of urban waste water that needs biological treatment ( million p.e.) is lower than the collected urban waste water ( million p.e).

Furthermore, the amount of urban waste water that needs biological treatment with removal ( million p.e.) is lower than the collected urban waste water ( million p.e.), because this type of treatment is necessary only for larger urban areas (over 10,000 p.e.), discharging into sensitive areas.

Have countries met the targets for urban waste water collection and treatment?

The compliance of the total generated load in the EU countries is %. This differs from the average EU compliance value of % shown in Figure 4 on the Country profiles, because that value is the average of the load from compliant agglomerations in 27 Member States.

Figure 3
Amount of urban waste water which still needs to be collected or treated according to the requirements of the UWWTD

Distance to target in million p.e.

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Map view 2
Urban areas compliance status

Zoom in to check if urban waste water in the urban area of your interest is collected and treated according to the requirements of the UWWTD (pop up window with detailed information opens when clicking on a point in the map).

What progress have countries made in meeting its targets for urban waste water collection and treatment?

Between and , :
- the required target for collection of urban waste water
- the required target for biological treatment of urban waste water
- the required target for biological treatment of urban waste water with removal

Figure 4
Recent trends in the amount of urban waste water which is not collected or treated according to the requirements of the UWWTD

Distance to target in million p.e.

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How is waste water sludge managed in countries?

generated tonnes of waste water sludge in :

% was reused in agriculture and other soil uses

% was reused in other uses

% was landfilled

% was incinerated

% was disposed in another way

% was managed without further information reported

Figure 5
The proportion of waste water sludge from treatment plants reused or disposed

Percentage of total waste water sludge generated

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Do countries reuse treated urban waste water?

Water reuse has become a key part of water resources management in countries suffering from high water stress. The primary use of reused water is in irrigation for agriculture. Other uses are in irrigation of urban space, such as parks and sports fields, groundwater recharge and river flow improvement. Where water resources are less stressed, waste water reuse is usually driven by other factors, such as conservation of groundwater resources.

More detailed national information is provided in the individual country profiles.

Map view 3:
Discharge of treated waste water

Zoom in to check where plants discharge treated waste water on land. Pop up window with detailed information opens when clicking on a point in the map. Select the "layers" tab in the right panel and the arrow to see and turn on/off the layers in the map.

Is there a decrease in greenhouse gas emissions by the urban waste water treatment sector in countries?

Figure 6
Trends in emission of greenhouse gases by the urban waste water treatment sector

Carbon dioxide emissions equivalent

In , emissions of greenhouse gases by the urban waste water treatment sector have by % between and .

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How do countries protect its most sensitive waters from algal blooms?

Too much nitrogen or phosphorus in water can cause algal blooms. This may affect fish, bathers and the wider environment negatively.

countries designated part or all of their territory as sensitive areas and decided to apply more stringent treatment with nitrogen and/or phosphorus removal. Further, details on the applied treatment per sensitive area are presented in individual country profiles and the map below.

Map view 4
Sensitive areas

Zoom in to see where plants discharge treated waste water. Green points show where the water is reused through discharge on land. Pop up window with detailed information opens when clicking on a point in the map. Select the "layers" tab in the right panel and the arrow to see and turn on/off the layers in the map.

By implementing the Water Framework Directive, countries have assessed the quality of national waters, including surface water bodies (e.g. rivers, lakes, transitional and coastal waters) and groundwater bodies. In addition, they have identified the pressures that contribute to less than good water quality (i.e., poor chemical status or less than good ecological status for their surface water bodies, and poor chemical status for their groundwater bodies).

Figure 7
Percentage of different water body types having less than good water quality, and being affected significantly by discharges of urban waste water, discharges from unconnected dwellings and storm water overflows in the latest RBMPs

Percentage of surface water bodies or groundwater bodies area

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Are waste water discharges a significant pressure for waters in countries?

According to the latest River Basin Management Plans (RBMPs) in :

Discharges of urban waste water contribute significantly to less than good water quality in:

% of river water bodies

% of lake water bodies

% of transitional water bodies

% of coastal water bodies

% of groundwater body area

Discharges of waste water from unconnected dwellings contribute significantly to less than good water quality in:

% of river water bodies

% of lake water bodies

% of transitional water bodies

% of coastal water bodies

% of groundwater body area

Discharges of storm water overflows contribute significantly to less than good water quality in:

% of river water bodies

% of lake water bodies

% of transitional water bodies

% of coastal water bodies

% of groundwater body area

Is there an increase in the number of monitored bathing water sites with excellent water quality in countries?

It is noted that bathing water sites are not necessarily affected by direct discharges of urban waste water. Therefore, observed water quality problems can also be related to other activities.

The monitored bathing water sites with excellent water quality in have between 2010 ( sites) and 2023 ( sites).