Facts & Figures

 ClientIrish Water
 LocationDublin - Ringsend, Ireland
 Operation Start2017
 Project TypeRetrofit
 Process ConfigurationPre-treatment + Primary settler + Nereda
 Nereda Design Capacity:
  • Dry Weather Flow600 MLD
  • Peak Flow50,000 m3/h
  • PE2,400,000 PE (PE = 60 gBOD/d)


The retrofit project to Ringsend wastewater treatment plant (WWTP) in Dublin extends treatment capacity to 2.4 million people equivalent (PE).

Ringsend is an inner suburb of the city of Dublin, Ireland. It is located on the south bank of the River Liffey and east of the River Dodder, about two kilometres east of the city centre.


The existing Ringsend WWTP was commissioned in 2003 and had a design capacity of 1.64 million population equivalent, capable of handling a flow of 11.3 m³/second. But prior to its upgrade it was operating over that capacity, at 1.9 million p.e. The principal effluent requirements were based on only Carbon (BOD and SS) removal. The existing WWTP consisted of 24 SBR tanks, stacked in a two-layer deck of 12 SBR tanks per deck. Each tank had a volume of 13,500 m³.


To address the overloading of the facility and related bottlenecks in the operation – and to introduce nutrient removal to meet the level of treatment required by the European-based Urban Wastewater Treatment Directive – a major upgrade of the plant at the existing site was proposed. Irish Water selected Nereda technology as part of the wide upgrade project in Dublin. The entire upgrade project will enable Ringsend WWTP to have the capacity to treat the wastewater of 2.4 million p.e. (144,000 kg BOD/d) and 600,000 m³/d, with a peak flowrate of 50,000 m3/h.

The major works of the project include the construction of a ‘greenfield’ plant expansion at the existing, undeveloped, 0.8-hectare site and retrofitting the existing SBR tanks, to increase treatment capacity. It also includes a review and assessment of the current sludge handling and treatment facilities, to accommodate the increased sludge production, and the evaluation of requirements for removal of phosphorous from the sludge stream. The current and required power requirements were reviewed and assessed, with regard to the current Maximum Import Capacity.


Image: Operacional Nereda Reactor


Overall completion of the Ringsend Project is estimated to be in 2027. One of the characteristics of the project is its scale, with 40% of all Irish wastewater treated in this facility. The project is a complex one, as the treatment plant must remain operational throughout the retrofit and there is only a small footprint available for extension.

To date, one of the SBR tanks has been retrofit to a Nereda plant and is fully operational. Royal HaskoningDHV is working on the project with its Irish partners, TJ O’Connor & Associates and J. B. Barry and Partners. The operation and maintenance of the plant is carried out by the Operator ‘Celtic Anglian Water’ (CAW).


Nereda® in brief: Ringsend, Dublin in ireland

View more information on the Dublin, Ringsend WWTP Process Proving Step 1 and 2 here.