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. The European Environment Agency (EEA) has published data which show that the share of urban waste waters that are collected and treated in line with EU standards is increasing across Europe.
The EEA’s new country profiles on urban waste water treatment present the latest data from all 27 EU Member States and Iceland and Norway on the implementation of the EU Urban Waste Water Treatment Directive. The country profiles contain interactive maps with waste water treatment plants across Europe. Each profile also shows data on the country’s progress towards waste water treatment targets, protection of sensitive water systems, use of waste water sludge, and greenhouse gas emissions from the waste water treatment sector.
The data show that waste water collection and treatment are improving across Europe. Across the whole EU, about 90% of urban waste waters are collected and treated in accordance with the EU Waste Water Treatment Directive.
Based on the country profiles, four countries – Austria, Germany, Luxembourg, and the Netherlands – treat 100% of their urban waste water in compliance with the Directive’s requirements, while 10 additional countries have reached more than 90% compliance rate. At the other end of the scale are five countries – Ireland, Bulgaria, Romania, Croatia and Malta – that comply in less than half of their urban areas according to the same standards.
Urban waste water needs to be treated adequately because it may contain bacteria, viruses, nitrogen, phosphorus and other pollutants which can pose a risk to the environment and human health.
The EU Urban Waste Water Directive sets out a time plan for the construction of infrastructure for collecting and treating waste water in urban areas. In general, waste water must be subject to biological treatment (“secondary treatment”), which removes a very high proportion of organic pollution, bacteria and viruses. To reduce the risk of algal blooms, further removal of nitrogen and/or phosphorus is required in larger urban areas that are connected to sensitive water bodies.
The new country profiles are published on the Water Information System for Europe (WISE) Freshwater platform, which is being developed into a unique entry point to access to data and information on the environmental status and policy assessments of European freshwater.
In Ireland, households and certain industries in 192 urban area generate 5.3 million p.e. of waste water every day, which is an amount equivalent to around 11 million bathtubs or 1.05 million m3. However, urban waste water needs to be treated before discharge, in order to avoid pollution to the environment. In Ireland, urban waste water is treated in 182 plants across the country before it is discharged.
What are the targets for urban waste water collection and treatment in Ireland?
According to the UWWTD, Ireland is required to provide in urban areas:
- Collection of 5.3 million p.e. of waste water
- Biological treatment to 5.0 million p.e. of waste water
- Biological treatment with nitrogen and/or phosphorus removal to 3.7 million p.e. of waste water
For 0.2 million p.e. of urban waste water, Ireland applies individual systems (e.g. domestic treatment plants; septic tanks), instead of centralised collecting systems and treatment plants. These alternatives are allowed by the legislation, as long as the environment is adequately protected.
In addition, for 0.09 million p.e. of urban waste water Ireland 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 (5.0 million p.e.) is lower than the collected urban waste water (5.3 million p.e).
Furthermore, the amount of urban waste water that needs biological treatment with nitrogen and/or phosphorus removal (3.7 million p.e.) is lower than the collected urban waste water (5.3 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 Ireland met the targets for urban waste water collection and treatment?
Ireland has met the targets for:
- Collection of urban waste water
Further efforts are needed to provide:
- Biological treatment to additional 2.51 million p.e of urban waste water (50.5%)
- Biological treatment with nitrogen and/or phosphorus removal to additional 2.77 million p.e. of urban waste water (75.1%)
Amount of urban waste water which still needs to be collected or treated according to the requirements of the UWWTD
Overall, 44% of the urban waste water in Ireland is treated according to the requirements of the UWWTD. This is below the EU average of 76%. The 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
Source – European Environment Agency