Major upgrade of Mullagh’s wastewater treatment plant
Uisce Éireann has submitted a planning application for a significant upgrade to the Mullagh Wastewater Treatment Plant (WWTP), a project designed to increase capacity and support future population growth in the area over the next 25 years.
The application relates to the existing Mullagh plant with associated infrastructure extending through the townlands of Rosehill, County Cavan, and Seancarnan, Moynalty, County Meath.
The proposed development would increase the plant’s treatment capacity from 3,000 population equivalent (PE) to 3,400 PE, providing additional capacity to accommodate planned residential and commercial development within the catchment area.
The proposed upgrade follows years of concern over capacity constraints at the Mullagh facility. The Environmental Protection Agency (EPA)previously identified the plant as a priority location requiring investment due to environmental compliance issues and limited capacity for future development.
The project proposes the demolition and decommissioning of ageing infrastructure, to be replaced by modern treatment processes.
The plans include extensive upgrades, as well as a new effluent pumping station and a 1.365-kilometre rising main along the R194 Mullagh Road to the Moynalty River.
The application also includes substantial improvements to sludge treatment facilities, new pumping stations, together with chemical dosing systems for sodium hydroxide and ferric sulphate.
Additional works would comprise a new motor control centre (MCC) building.
The scheme forms part of a wider programme of wastewater investment across County Cavan. Uisce Éireann, working with Cavan County Council, previously announced a €1.4M programme of upgrades at wastewater treatment plants in Blacklion, Kilnaleck, Shercock, Ballyhaise, Killeshandra and Mullagh, with works focusing on inlet infrastructure, stormwater management and sludge treatment.
The Mullagh project has previously been identified as one of a number of nationally important wastewater schemes whose completion has been delayed, with delivery timelines extending into the latter part of the decade.
The need for improvements was highlighted in 2023 when Irish Water was prosecuted by the EPA over failures to complete upgrades at a number of overloaded wastewater treatment plants around the country. During those proceedings, inspectors found elevated orthophosphate levels at the Mullagh plant, with the utility pleading guilty to breaches of its wastewater discharge licence. The utility was fined €7,000 by Dublin District Court as part of the case.
A decision on the new application is due by September 1.