Carlow (Mortarstown) Wastewater Treatment Plant Upgrade

Uisce Éireann is progressing plans to upgrade the wastewater infrastructure for Carlow Town and surrounding areas, including Graiguecullen and parts of Crosneen, Co. Laois. The proposed project will enable future growth and development in the region, while also improving water quality in the River Barrow, benefitting the environment, ecology, sporting, and tourism activities.

The project proposes that the existing capacity at the Mortarstown Wastewater Treatment Plant be increased from the current population equivalent (pe) of 36,000 to 58,000, to meet anticipated growth in the region and future demands of the town. 

In addition, upgrades to the treatment process are required to ensure continued environmental compliance and improve water quality in the River Barrow. 

Improvements to the wastewater pumping station at Kilkenny Road and the construction of a new pumping station next to the existing Mortarstown Wastewater Treatment Plant site are also proposed. These two stations will be linked by a newly constructed tunnel. 
 

Upon completion the project will:
 

• Enable future growth and development in the community and cater for an expected increase in population in the area.
• Enhance Carlow’s amenity value by providing a cleaner environment and act as a platform for social and economic development.
• Improve water quality in the River Barrow, benefitting the environment, ecology, sporting and tourism activities.
• Ensure that wastewater will be treated in accordance with European Union Urban Wastewater Treatment Directives and Environmental Protection Agency wastewater discharge licensing.

Uisce Éireann is engaging with the local community and stakeholders regarding the proposed project through a non-statutory consultation process before the formal planning application is submitted to An Coimisiún Pleanála (previously known as An Bord Pleánala) in the coming months.

This non-statutory consultation will run for four weeks from Monday 22 September to Sunday 19 October 2025.

Uisce Éireann is holding a face-to-face public information event in the local area where you can meet the project team and ask any questions you may have on the proposed project. Details of the event are as follows:

• Thursday 9th October 2025, 4:00-8:00pm
• Seven Oaks Hotel and Leisure Club, Athy Road, Carlow, Ireland, R93V4K5

Further details on the project, including how to participate in the consultation and upcoming public information events, are available on www.mortarstownwwtp.ie.