Castletroy Wastewater Treatment Plant

Uisce Éireann is commencing works to upgrade Castletroy WWTP in Castletroy, Co Limerick.

Uisce Éireann is commencing works to upgrade the Castletroy Wastewater Treatment Plant (WWTP) to support existing and future population and economic growth, following an investment of over €32m.

Castletroy WWTP has been providing wastewater treatment to the area since the early 1990's. It serves the East Limerick suburbs of Castletroy, Annacotty, Mountshannon and Castleconnell, as well as the University of Limerick and other local industry.

The WWTP is currently operating at the upper limits of its capacity and Uisce Éireann has identified that an upgrade is required.

The upgrade will increase the current plant's capacity by over 70% and provide stormwater storage for heavy rain events. These works will ensure wastewater is treated appropriately now and into the future, supporting economic and population growth in East Limerick.

Works on the project will commence in July 2025 and are expected to be completed in Q3 2027.  Coffey Construction (Ireland) Ltd. is carrying out these works on behalf of Uisce Éireann.

The works will include:

• Construction of a new 4,500m³ stormwater storage tank
• Installation of new primary treatment filters and lifting pumps
• Construction of a new primary sludge holding tank
• Upgrade of the existing secondary treatment tanks to provide additional capacity
• Upgrade of the plant's sludge treatment facilities

• Modernise and improve the performance of the existing wastewater treatment plant
• Improve the health and integrity of the environment
• Protect the water quality in Lower River Shannon and conservation habitats
• Provide sufficient capacity to facilitate future population and industrial growth
• Protect recreational waters for fishing and boating activities
• Ensure compliance with Irish and EU legislation now and into the future
• Ensure compliance with national and EU regulations relating to the treatment of wastewater