Uisce Éireann has been convicted and fined €4,000 for the pollution of the Ballinagh River in Cavan in which approximately 160 fish perished.
It's the third time since 2015 that Uisce Éireann has been prosecuted for pollution of the river near their Ballinagh water treatment plant.
Cavan District Court heard how Inland Fisheries Ireland were alerted to a fish kill on the Ballinagh River on July 19th last year.
During an immediate investigation by the IFI, water samples were taken for analysis and the results indicated the pollution source was direct discharge from an effluent pipe at Uisce Éireann's wastewater treatment plant.
Approximately 160 fish, predominantly brown trout, perished in the incident, and that number also included some stickleback and minnow."
Director of IFI's North-Western River Basin District, Dr Milton Matthews, said "high levels of ammonia are toxic to fish and can have a prolonged impact on native fish stocks, which may take many years to recover."
Uisce Éireann were also ordered to pay costs of €3,079 in the case.
Members of the public are encouraged to report instances of water pollution, illegal fishing or fish kills to Inland Fisheries Ireland on their confidential telephone number 0818 34 74 24.
