Carrickmacross Wastewater Treatment Plant Upgrade

Uisce Éireann, working in partnership with Monaghan County Council, is progressing with works on the Carrickmacross Wastewater Plant Upgrade.

This €32 million investment will benefit homes and businesses in Carrickmacross and will ensure wastewater from the town and surrounding areas is treated appropriately and will serve a population equivalent of 16,000 PE.

The project involves an upgrade to the Wastewater Treatment Plant, along with construction of a new final effluent pumping station and a new 3.3km final effluent pipeline to the Longfield River. These improvements will enhance the water quality of the receiving waters.

When completed, the project will ensure effective management of wastewater to protect the environment and support social and economic growth in the area.

The works will ensure the treatment of wastewater is fully compliant with EU Urban Wastewater Treatment Directives and Wastewater Discharge Licence Emission Limit Values and will eliminate all non-compliant combined sewer overflows within the area.

EPS Group is working on behalf of Uisce Éireann to deliver these works. The project is expected to be concluded in 2026.

We've successfully relocated the effluent outfall from the Proules River to the Longfield River downstream of Monalty Lough. We've also finished installing: a new inlet for collecting and pumping untreated wastewater into the plant, a final effluent pumping station to manage the discharge of treated water, and a 3.5 km rising main to the Longfield River. The strategic outfall relocation is anticipated to significantly enhance water quality in both Monalty Lough and the Proules River and will ensure compliance with requirements set out in the EPA license.

Works have recently commenced on the upgrade of the Wastewater Treatment Plant in Carrickmacross, including the installation of a new storm tank for flood protection and pollution reduction. A new sludge hub will also be included in the upgrade project and will decrease sludge volumes generated at the plant by removing water. Other mechanical and electrical upgrades will also be completed at the plant as part of the project.

We have successfully completed the following works: 

• Relocation of the outfall pipeline from the Proules River to the Longfield River
• Upgrade of the existing Wastewater Treatment Plant
• Construction of the outfall pipeline discharging to the Longfield River
• 3.5km of rising main to the Longfield River
• Construction of the new Oriel Road entrance to the WWTP

Upon completion the project will:

• Improve water quality and integrity of receiving waters benefitting fishing and other water sports.
• Enhance Carrickmacross’ amenity value due to a cleaner environment, and thus acting as a platform for social and economic development.
• Ensure that wastewater will be treated in accordance with EU Urban Wastewater Treatment Directives and Environmental Protection Agency wastewater discharge licensing.
• Overcome/design a number of significant issues adversely affecting the operation and maintenance of the plant.