Croatia

Overview: urban waste water production and its treatment

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.

However, urban waste water needs to be treated before discharge, in order to avoid pollution to the environment. In , 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 in ?

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 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.

Has met the targets for urban waste water collection and treatment?

Overall, % of the urban waste water in is treated according to the requirements of the UWWTD. This is the EU average of %.

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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Figure 4
Proportion of urban waste water that meets all requirements of the UWWTD (collection, biological treatment, biological treatment with nitrogen and/or phosphorus removal) in compliant urban areas

Compliance rate %

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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 has made in meeting its targets for urban waste water collection and treatment?

Between 2018 and , :
- has decreased its distance from the required target for collection of urban waste water
- has decreased its distance from the required target for biological treatment of urban waste wate
- has decreased its distance from the required target for biological treatment of urban waste water with nitrogen and phosphorus removal

Figure 5
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 ?

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 6
The proportion of waste water sludge from treatment plants reused or disposed

Percentage of total waste water sludge generated

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Does reuse treated urban waste water?

Map view 3:
Discharge of treated waste water

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.

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

Figure 7
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 does protect its most sensitive waters from algal blooms?

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

designated of its territory as sensitive areas and decided that agglomerations over 10,000 p.e. discharging into sensitive areas must apply biological treatment with removal.

Map view 4
Sensitive areas

Zoom in to check the sensitive areas and if the treatment plant in the urban area of your interest discharges into a sensitive area. 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 8
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

Hover over the bars to see the number of surface water bodies and areas (Km²) of groundwaters affected by urban waste water.

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Are waste water discharges a significant pressure for waters in ?

According to the 3rd 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 from storm water overflows are not reported as significant pressures.

% 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 ?

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).

More information

Croatia applies Article 5(2-3) of the Directive. Consequently, all agglomerations >10,000 p.e. in the country and discharging into sensitive areas must comply with Article 5 (apply more stringent treatment than secondary i.e. nitrogen and/or phosphorus removal). Croatia has designated 81 sensitive areas.

In line with the requirements under their Accession Treaty, compliance with the main requirements of the Directive must have been partially achieved in Croatia by 2020 and fully achieved by 2022. Croatia did not report compliance information prior to 2020. The distance to target (Figure 3 & 5) shows what must be achieved by 2022.

For the reporting years 2018 and 2020 Croatia had a number of urban areas (agglomerations), which were not subject to compliance evaluation, due to pending deadlines. Therefore, only 74 urban areas out of 245 in total were assessed for compliance. The same should be applied also for the reporting year 2022, since all pending deadlines expired at 31.12.2023."

Croatia did not report their current investments (Figure 10). However, their expected annual investment costs per capita for installing and renewing waste water collecting systems and treatment plants is 105 EUR/inhabitant/year.