Uisce Éireann has announced the completion of the €550 million upgrade of the Ringsend Wastewater Treatment Plant (WWTP), supporting increased wastewater capacity for housing and economic growth.

The Ringsend Wastewater Treatment Plant has been treating Dublin’s wastewater since 1906 and currently treats 40% of all public wastewater in Ireland, servicing the four Dublin local authority areas and parts of Counties Kildare and Meath.

The plant was last upgraded in 2005, delivering secondary treatment for the equivalent of 1.64 million people. In the years since that upgrade, Ringsend WWTP has repeatedly operated beyond its design capacity. Rapid population growth, economic expansion, and intensified development have placed substantial pressure on the plant.

The completed project now provides treatment capacity for the equivalent of 2.4 million people. The upgrade delivers advanced nutrient removal, ensuring compliance with Urban Wastewater Treatment Directive requirements and significantly improving the quality of the receiving waters of the Lower Liffey Estuary and Dublin Bay. 

Uisce Éireann's decision to use innovative Nereda® technology made it possible to expand the plant’s treatment capacity from 1.6 million to 2.4 million population equivalents within the existing site — delivered on time and within budget.

James Browne T.D., Minister for Housing, Local Government and Heritage, noted the critical importance of the investment:

“The upgrade of the Ringsend Wastewater Treatment Plant represents the State’s largest-ever investment in wastewater treatment and directly responds to the demands of a growing population as well as to EU obligations and environmental needs. This project not only enables compliance with our EU obligations, but also ensures that communities, homes, and businesses across the Greater Dublin Area can continue to grow sustainably.

"I want to acknowledge Uisce Éireann’s significant work in delivering this complex upgrade on time and on budget, while keeping the plant fully operational. The Government is providing unprecedented levels of funding for water infrastructure under the National Development Plan, and many more projects are being progressed to facilitate economic growth and housing delivery, while protecting our environment.”

CEO of Uisce Éireann Niall Gleeson commented:

“This is a landmark day for the Greater Dublin Area and for Ireland’s environmental future. Rapid population growth, sustained economic expansion, and intensified development had placed substantial and ongoing pressure on Ringsend Wastewater Treatment Plant - pushing it well beyond its original design capacity. The completion of Ringsend Wastewater Treatment Plant allows Ireland to meet its urban wastewater standards to protect the environment and will allow for the region to continue to grow, providing much needed water infrastructure for homes and businesses.

"This completion is the first of two critical projects; work has already begun on the Greater Dublin Drainage (GDD) project, which will provide additional network and treatment capacity for communities so that Ringsend is no longer required to manage the full load of the Greater Dublin Area. The delivery of these strategic investments will secure the resilience of the region’s wastewater services for decades to come.”