Wastewater

Municipal wastewater treatment

Inadequate management of municipal wastewater is one of the core problems in the Danube River Basin.

The contamination of groundwater and rivers with untreated wastewater can be harmful in many ways and the long-term effects of such pollution reduce biodiversity in aquatic ecosystems, and affect human water uses, such as drinking water sources.

The contamination of groundwater and rivers with untreated wastewater from residential, commercial, and industrial areas can be environmentally harmful in many ways. Microorganisms can spread disease; the decomposition of organic materials can cause oxygen depletion in rivers, lakes, leading to the release of foul-smelling gases. Toxic substances in wastewater can accumulate in living organisms; and the nutrients in wastewater also worsen eutrophication.

The long-term effects of such pollution are also reduced biodiversity in aquatic ecosystems, and shortages of suitable drinking water sources due to the presence of harmful nitrogen compounds and other contaminants. All these factors reduce the development potential of the regions affected.

Facts and figures

• Fewer than half of all households in the middle and lower Danube regions are connected to central sewerage systems
• Almost a third of all municipal wastewater is discharged untreated
• Treatment facilities have insufficient capacities and are widely operated in an unsuitable way
• Smaller wastewater treatment facilities for individual buildings such as septic tanks are insufficiently controlled.
• Four Danube countries treat almost all collected municipal wastewater. Five countries treat less than 70% of all the collected domestic wastewater and only one clean 45%.
• Most of the Danube countries are actively working to improve the removal of nitrogen and other nutrients at municipal wastewater treatment plants.

The great differences in the technical levels of wastewater treatment between the Danube countries may be attributed to differences in overall levels of economic development and particularly to the current economic difficulties being endured by countries undergoing transition from centrally planned to open marked economies.

Did you know? You can help too

Certain products can cause serious water pollution. A large proportion of the total phosphorus discharge may originate from household detergents, for instance. Do not allow the following wastes to enter sewerage systems:

• Paints (containing heavy metals and other hazardous substances)
• Organic solvents
• Motor oil and other oils
• Pharmaceutical wastes
• Plastics
• Heavy metals, such as mercury in thermometers
• Chemical products

What the ICPDR is doing

The ICPDR is working to ease the burden of pollution in the Danube River Basin and the Black Sea originating from municipal, industrial, and agricultural point sources by facilitating the construction of a number of wastewater treatment plants, according to the Joint Action Programme (2001 -2005).

Total investments are expected to amount to almost €4 billion for wastewater treatment plants serving settlements, and about €300 million for process-related measures and wastewater treatment plants in industrial and agricultural point sources.

It is important that the real costs of providing and treating water are fully understood by consumers, especially in major urban areas. Governments can only secure improvements through large investment projects if users help to cover the costs.

The EU DABLAS Project

Under the EU DABLAS project, four Danube countries have listed in 2002 a total of 45 municipal investment projects, including wastewater treatment plants with a total investment cost of €622.6 million. The expected total reductions in organic matter (expressed in BOD = biological oxygen demand), chemical oxygen demand (COD), total nitrogen and total phosphorus are presented in the table below, in tonnes per year.

191 municipal sector investment projects (representing a population equivalent of more than 27 million) were identified as part of the DABLAS 2004 assessment, as compared to 158 projects documented in 2002. Considering the pollution reduction (BOD, COD, Total N, Total P) expected through the 354 DABLAS 2004 investments, approx. 5% of the reduction has been achieved by projects completed by 2003.  The rate increases to 10-15% by 2005, while 85-90% of the expected pollution reduction will be carried out through projects completed after 2005.

Existing and planned measures for pollution reduction concentrate on the most urgent objective to reduce the load from municipal wastewater.
Regulatory demands regarding implementation of tertiary treatment are variable among the Danube countries, depending primarily on how the sensitivity of surface water resources have been classified in national legislation.  The majority of the projects in the Czech Republic, Hungary, Slovakia, Slovenia, Bulgaria and Romania have tertiary treatment technology(i.e. the removal of the nutrients nitrogen and phosphorus). This is a result of legislative transposition during the EU accession period of the EU Urban Waste Water Directive.

Disclaimer

The information contained in the ICPDR website is intended to enhance public access to information about the ICPDR and the Danube River. The information is correct to the best of the knowledge of the ICPDR Secretariat. If errors are brought to our attention we will try to correct them.
The ICPDR, expert group members, nor other parties involved in preparation of information contained on this website cannot, however, be held responsible for the correctness and validity of the data and information provided, nor accept responsibility or liability for damages or losses arising directly or indirectly from the use of the information conveyed therein.
Only those documents clearly marked ICPDR documents reflect the position of the ICPDR.
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When using the information and material provided on this website, credit should be given to the ICPDR.