Ringsend Wastewater Treatment Plant Upgrade Project

A major upgrade is underway to the Ringsend Wastewater Treatment plant which will enable increasing volumes of wastewater arriving at the plant to be treated to the required standard, enabling future housing and commercial development.

Wastewater from Dublin has been treated in Ringsend since 1906. Built in 2005, the current plant is the largest in Ireland and was designed to cater for an equivalent of 1.64 million people. The Ringsend Wastewater Treatment Plant (WwTP), which provides over 40% of Ireland's wastewater treatment capacity, is currently overloaded and is not in compliance with the EU's Urban Wastewater Treatment Directive.

Uisce Éireann is investing over €500 million in the staged upgrading of Ringsend Wastewater Treatment Plant. This major upgrade is now underway and will allow the Ringsend WwTP to treat the increasing volumes of wastewater arriving at the plant to the required standard, enabling future housing and commercial development. The project will deliver, on a phased basis, the capacity to treat the wastewater for a population equivalent of 2.4 million while achieving the standards of the Urban Wastewater Treatment Directive.

What is involved in the project?

The project is being progressed in stages to ensure that the plant continues to treat the wastewater (1.98 million population equivalent) to the current treatment levels throughout the delivery of the upgrade works. The project comprises four key elements and underpinning these is a substantial programme of ancillary works:

1. Provision of additional secondary treatment capacity with nutrient reduction; (400,000 population equivalent)
   Status: now complete
    
2. Upgrade of the 24 existing secondary treatment tanks to provide additional capacity and nutrient reduction; (essential to protect the nutrient-sensitive Dublin Bay area)
   Status: works continuing to provide the 2.4 million population equivalent capacity
    
3. Provision of a new phosphorous recovery process;
   Status: now complete
    
4. Expansion of the plant's sludge treatment facilities.
   Status: works continuing to provide the 2.4 million population equivalent capacity

What are the benefits of this project?

• Once complete the upgrade will increase capacity at the plant to a population equivalent of 2.4 million, enabling future housing and commercial development.
• Modernise and improve the performance of the wastewater treatment infrastructure
• Safeguard human and environmental health.
• Ensure compliance with National and European regulatory standards regarding the treatment of wastewater.
• The use of Aerobic Granular Sludge (AGS) nutrient reduction treatment technology at Ringsend will maximise treatment capacity and efficiency at the plant.
• A much higher treated effluent quality would also be achieved and, even at full future capacity, emissions from the plant would be significantly lower than at present.
• The project provides for the recovery of phosphorus (a non-renewable resource). Recovery of this finite resource will prevent it from being discharged into Dublin Bay and allow it to be re-used in agriculture. 

Uisce Éireann completed construction of the infrastructure to treat the wastewater for a population equivalent of 2.1 million at the end of 2023. Following a period of testing and commissioning the upgraded assets are operational.

Compliance with the Urban Wastewater Treatment Directive is assessed retrospectively based on the attainment of 12 months compliance with the UWWTD Emission Limit Values (ELVs). We are monitoring the performance of the plant closely with a view to achieving this at the earliest possible time. We are also continuing works on the remaining project elements to deliver the capacity for a population equivalent of 2.4 million by the end of 2025.