Inland Fisheries Ireland (IFI) has gained a conviction against Uisce Éireann following a wastewater treatment plant discharge into a wild brown trout habitat.

Uisce Éireann was found to have committed pollution breaches relating to the Balla wastewater treatment plant, Co Mayo, and must now pay €3,165 in connection with the case.

The incident happened at the Rodney River, a tributary of the Manulla River in Co Mayo.

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Director of IFI's western region (Ballina) Mary Walsh said: "IFI welcomes the outcome of this case and will continue to monitor and protect this vulnerable river habitat.

"This catchment is under environmental pressure and requires robust protection. Fortunately, no fish died as a result of the pollution.

"The discharge of poorly-treated sewage from the Balla wastewater treatment plant increased the nutrient concentration of the river water.

"This can make it less suitable to sensitive fish species such as brown trout and the insects they feed on,” she said.

The case was heard at Castlebar District Court on 20 November 2025.

Uisce Éireann was instructed to pay a fine of €750 and ordered to pay costs and expenses of €2,415 to IFI.

The pollution incident occurred on 20 May 2025.

Response

In a statement to the Irish Farmers Journal, Uisce Éireann said it is committed to safeguarding public health and protecting the environment in all its activities.

“An overflow incident occurred at Balla wastewater treatment plant in May 2025. On becoming aware of the incident, Uisce Éireann took measures to address it and co-operated fully with Inland Fisheries Ireland in relation to their investigation.

“There was no fish kill associated with the incident.

“Uisce Éireann pleaded guilty at a recent court sitting to a charge of causing deleterious matter to enter the waters.

“Uisce Éireann has put a number of measures in place to ensure such an incident does not recur. Further measures are planned and will be delivered as soon as possible in 2026. Increased periodic sampling is also now taking place,” a spokesperson for the company said.

Scale of the task

In 2014, Uisce Éireann took over responsibility for water and wastewater services from 31 local authorities.

“Given the scale of that task, Uisce Éireann has inevitably encountered challenges and has had to address weaknesses across the system.

"Since Uisce Éireann’s establishment, over €10bn has been invested to upgrade water and wastewater treatment plants and networks.

"This work is ongoing and will require sustained high levels of funding across multiple investment cycles to address legacy issues and enable us to transform Ireland’s water and wastewater services.”