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./emeb

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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 2014 and 2018,  :
-   the required target for collection of urban waste water
-   its distance from the required target for biological treatment of urban waste water
-   its distance from the required target for biological treatment of urban waste water with   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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Does   reuse treated urban waste water?

 

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 2019.

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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 affect fish, bathers and the wider environment negatively.

  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 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).

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

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Are waste water discharges a significant pressure for waters in  ?

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 bodies 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 bodies 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 bodies 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   (  sites).

Figure 9
Progress in the number of monitored bathing water sites having excellent water quality in recent years

Number of monitored bathing water sites

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More information

Bulgaria applies Article 5(2-3) of the Directive. Consequently, all agglomerations >10,000 p.e. that discharge into a sensitive area must comply with Article 5 (apply a more stringent treatment than secondary, i.e. nitrogen and phosphorus removal).
Bulgaria has designated 14 sensitive areas and 14 catchments of sensitive areas, where nitrogen and phosphorus removal is necessary to avoid eutrophication.