Project Background

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. The average daily load received at Ringsend Wastewater Treatment Plant in 2019 was 1.98 million population equivalent with peaks well in excess of this.

Ringsend, Dublin
In Progress
An infographic showing the plans in place at Ringsend Wastewater Treatment Plant

The major upgrade that is now underway 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. 

Irish Water is working to provide infrastructure to achieve compliance with the Urban Wastewater Treatment Directive for a population equivalent of 2.1 million in the second half of 2023. When all the proposed works are complete in 2025, the Ringsend Wastewater Treatment Plant will be able to treat wastewater for up to 2.4 million population equivalent while meeting the required standards.

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. 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);
  2. Upgrade of the 24 existing secondary treatment tanks to provide additional capacity and nutrient reduction, which is essential to protect the nutrient-sensitive Dublin Bay area;
  3. Provision of a new phosphorous recovery process; and
  4. Expansion of the plant’s sludge treatment facilities.

What is happening now?

In February 2018, the work commenced on the first element, the construction of a new 400,000 population equivalent extension at the Ringsend Wastewater Treatment Plant.  These works are at an advanced stage with testing and commissioning stages expected to be completed in the second half of 2021. 

Image shows the construction of the capacity upgrade at Ringsend Wastewater Treatment Plant
Construction of the Capacity Upgrade at Ringsend WwTP
Construction of the Capacity Upgrade at Ringsend WwTP July 2019
Construction of the Capacity Upgrade at Ringsend WwTP July 2019

Works on the first of four contracts to upgrade the secondary treatment tanks at the plant with Aerobic Granular Sludge (AGS) Technology commenced in November 2020. The addition of AGS technology will allow more wastewater to be treated to a higher standard within the existing tanks. The second contract is at procurement stage and is expected to commence in Q3 2021, following the completion of the capacity upgrade contract. These contracts are phased to ensure that Ringsend WwTP can continue to treat wastewater from the homes, businesses, schools and hospitals of the Greater Dublin Area at current treatment levels throughout the upgrade works.

In March 2021, the contract for the construction of the Phosphorous Recovery Facility was awarded to Murphy International Ltd. Construction is expected to take approximately two years. The Phosphorous Recovery Facility will be built within the confines of the existing Ringsend Wastewater Treatment Plant. It will operate in tandem with the Aerobic Granular Sludge technology being installed in the wastewater treatment plant, to reduce the levels of phosphorous being discharged into the lower Liffey Estuary. This will safeguard the environment of Dublin Bay, and ensure that the plant operates in compliance with the Urban Wastewater Treatment Directive standards.

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