Priority urban areas where treatment needs to improve

Aerial photo of Tubbercurry WWTP

There are deficiencies in many public sewers and waste water treatment plants, due to a legacy of under-investment.  

Consequently, waste water from some areas discharges into the environment without adequate treatment.  It will not be possible to fix all these problems in the short term, and therefore Irish Water must ensure that the resources that are available are directed where they are most needed.  We have identified the priority urban areas where treatment must improve in order to resolve national environmental priorities. 

You can see the full list of priority urban areas and the environmental issue at each area at this link.  This also shows when and how Irish Water plans to resolve the priority issue at each area.  There is further information on the priority areas in the EPA’s latest  Urban Waste Water Treatment Report.

The number of priority areas where treatment needs to improve has decreased from 148 in 2017 to 97 in 2021.

Priority Areas

Compliance with the Urban Waste Water Treatment Directive

In 2020, treatment at 12 of Ireland’s 174 large urban areas failed to meet European Union standards set to protect the environment.  The graph shows the decrease since 2017 in the number of areas not meeting these standards.

Over half (54%) of all the waste water collected in Ireland’s public sewers is collected in the 12 areas that failed the standards.  The failure of Ringsend treatment plant to meet the required standards is of particular concern because it treats waste water from a population equivalent of over 2 million.


Compliance with Urban waste water treatment directive

Raw sewage  

In 2021 untreated waste water (raw sewage) from the equivalent of 75,000 people still flows into the environment every day from 34 towns and villages.

Irish Water had planned to eliminate discharges of raw sewage from 29 of these 34 areas by the end of 2021. Irish Water will not meet this plan and it now expects to connect just one of these areas to treatment in 2021. Twelve areas are likely to continue discharging raw sewage after 2024 and two of these will not be connected to treatment until 2027. The chart shows the number of areas that will still have no waste water treatment plant at the end of each year, based on Irish Water’s latest plans.

16 areas that were discharging raw sewage have been connected to treatment plants since 2014.


Raw Sewage

Significant pressures on water quality

Coastal water

If waste water is not properly treated before it is released into the environment it can adversely impact the quality of rivers, lakes and coastal waters.  The EPA are prioritising 42 areas where waste water is a significant pressure on inland and coastal waters at risk of pollution. 

Improving treatment at these areas will help protect and improve the quality of the local environment, which will in turn support local communities, healthy ecosystems and a diverse range of plants and animals. 





Urban waste water collecting systems

Storm water overflow pipe into stream

Ireland’s waste water collecting systems include thousands of kilometres of underground sewers and pumping stations that carry sewage from our homes and communities to treatment plants.  In 2019 the Court of Justice of the European Union ruled that collecting systems serving some areas were inadequate.  When a collecting system is inadequate it cannot retain all the waste water collected in the sewer and convey it for treatment.

Irish Water must complete improvements on 7 priority collecting systems to bring the systems up to standard and resolve the issues highlighted by the Court.



Pearl Mussel

Pearl Mussel

The EPA is prioritising 12 towns and villages where waste water treatment must improve to protect freshwater pearl mussels that live in the rivers downstream of waste water discharges.  The freshwater pearl mussel is a globally endangered mollusc that requires clean, fast flowing, well oxygenated rivers and a clean river bed. 

The mussels are declining both nationally and internationally due to deteriorating river quality.  Pollution, for example from inadequately treated waste water, can be detrimental to the survival of new generations of mussels.