IRISH WATER HAS been fined €7,000 for failing to carry out upgrades to overloaded treatment plants around the country, causing “toxic” effects for fish and aquatic life in local rivers.

The Environmental Protection Agency (EPA) prosecuted Ireland’s national water utility over the disrepair found at facilities in Tipperary, Louth, Cavan, Donegal, Kerry and Clare.

The plants had all been due for upgrade but deadlines have been pushed back to 2029.

The case came before Dublin District Court today when Irish Water admitted breaking the terms of its licence.

Judge Halpin heard that rivers or streams where the facilities discharged treated water had increased levels of carbonaceous, biochemical oxygen demand, ammonia, orthophosphate, and suspended solids, which greatly exceeded limits set by the EPA.

EPA inspector Dr John Feehan said that this resulted in the “explosive growth” of algae and vegetation, which “mopped up” oxygen and could have had a “toxic” effect on fish and aquatic life.

Dr Feehan said the plant at Mullinahone, Co Tipperary, discharged into the Mullinahone stream, causing “poor quality” water. He said the water from the plant had 30 times the set limit for ammonia and 46 times the limit for orthophosphate. It was supposed to have been upgraded by 2015.

The plant at Duleek, Co Louth, was due to be modified by 2019. EPA inspector Jonathan Hughes said it discharged into the White River. Samples from it showed it had seven to ten times the orthophosphate limit.

EPA inspector Donal Howley said the plant Mullagh, Co Cavan, had 10 times the orthophosphate limit.

The plant at Kilmacrennan, Co Donegal, was designed to serve 500 people and was now “significantly overloaded,” said EPA inspector Liam O Suilleabhain.

It now served 800, and samples from the Lurgy river showed a 15-fold increase in biochemical oxygen demand in the water.

He said it impacted on pearl mussels downstream which required high-quality water. The ammonia levels were ten times the set limit.

The upgrade will not be complete until 2026, the court heard.

Dr Feehan described the plant at Abbeydorney, Co Kerry, as “very basic”, and it remained “grossly overloaded” despite being due to be upgraded by 2018.

Treated water flows into the Abbeydorney river, which was “grossly polluted”.

The court heard that there was no access road to the plant at Miltown Malbay in Co Clare, which created maintenance difficulties. As a result, it was “desludged” just once a year.

“As a result, the plant cannot be operated optimally,” said Dr Feehan.

The discharge flows through an open drain before joining another stream bringing the treated water to Spanish Point.

Samples from the stream had 300 times the limit for ammonia in the water.

Irish Water had 21 prior convictions for breaching wastewater regulations.

Defence counsel Eoghan Cole said Irish Water was not a private organisation operating for profit and that plants at other locations had to be prioritised. A list of 50 plants identified was now down to 34, he told the court.

The site in Clare was on private property, and ownership rights to the surrounding lands had to be secured.

The defence said the plants would be included in Irish Water’s next five-year plan commencing in 2024.

Judge Halpin noted the guilty plea and that Irish Water cooperated and had a good relationship with the EPA and its plans to address the problems at each site.

The court heard the problems did not result in public health issues and Irish Water had agreed to pay the EPA’s costs.