Major milestone as south Mayo wastewater upgrade passes halfway stage

A major €17.9 million investment is transforming wastewater infrastructure in Claremorris, providing increased treatment capacity to support the growing south Mayo town now and into the future.

Work on the significant upgrade to the Claremorris Wastewater Treatment Plant began in October 2025 and has now passed the halfway mark. The project will increase the capacity of the existing plant to cater for the town’s expanding population, with completion firmly on track for late 2027.

The upgrades will increase the design capacity of the plant by over 50%, from the currently population equivalent (PE) of 5,333 to a PE of 8,800 upon completion. This additional treatment capacity will allow for new residential and commercial developments in Claremorris and its hinterland, enabling the town and its communities to thrive in the years ahead.

Patrick Greene, Uisce Éireann portfolio manager, said works on the project are progressing well. “We have reached the mid-point of this significant upgrade to the plant, and we are delighted with how works have progressed to date. This is a major investment in the wastewater infrastructure of Claremorris, which will deliver a range of benefits for local communities.

“As well as boosting the capacity of the plant, the upgraded infrastructure will help to protect the local environment and the receiving waters by modernising the treatment processes to achieve biodiversity conservation and meet our obligations under the Water Framework Directive,” said Patrick.

The ongoing works at the plant include upgrades to the inlet and aeration systems, construction of a new settlement tank, and upgrades to sludge treatment and handling facilities. The works are being carried out by Veolia on behalf of Uisce Éireann and are on course to be complete by Q4 of 2027.

Uisce Éireann is grateful to the community of Claremorris and the surrounding areas for their support while this significant project is underway, and will continue to keep local residents, businesses and stakeholders informed as works progress toward their conclusion.