Irish Water has pleaded guilty to polluting a Co Louth stream after a malfunction at a sewage treatment plant led to a discharge which turned water grey.
However, they have been given a chance to avoid a criminal record after Judge John O'Neill ordered the utility to donate €2,000 to charity.
Irish Water was prosecuted by the Environmental Protection Agency (EPA) for failing to ensure sewage waste from a water treatment plant at Tinure in Co Louth did not cause pollution.
Prosecution solicitor Maeve Larkin told Judge O'Neill at Dublin District Court that the offence can result in a conviction with a maximum €5,000 fine.
EPA inspector Dermot Burke told the court that on June 4 last he went to the treatment plant and verified that discharge from the facility went into a fast flowing stream which is a tributary of the White River.
He said he saw a grey-coloured discharge going into the stream. Mr Burke could see sewage fungus in the water which is normally an indicator of pollution.
The court heard that 50 metres downstream from the point where the sewage waste entered, the water was still grey.
Photos of the pollution and the area were handed in to Judge O'Neill.
Samples were taken and analysed to measure biochemical oxygen demand (BOD) and ammonia levels in the water. Mr Burke explained high BOD means less oxygen for plant and water life.
There should be no more than 1.5 mgs of BOD per litre in the water but on the day he took samples downstream of the discharge, the level was 10mgs per litre.
A high rate of ammonia can be poisonous to fish, he also said. There should be 0.065 mg per litre in the water but on the day he took samples there was was 2.4mgs of ammonia per litre, “36 times the concentration of what should be in water”.
Ten metres upstream the the levels were below the required standard.
Mr Burke agreed with defence counsel Eoghan Cole that an electrical fault had caused a two pumps, one of which was a back-up, to go offline.
The EPA inspector also agreed that he gave Irish Water directions about what they should have done. Testing continued and after two weeks the water returned to its previous excellent levels, the judge was told.
Mr Cole asked the court to note that Irish Water has no prior criminal convictions and taxpayers would not be bearing the cost of the prosecution.
He suggested that imposing a fine would result in the transfer of money from one State bank account to another.
Judge O'Neill noted there was no environmental damage or fish kill and Irish Water co-operated fully.
He said it was low on the scale of such incidents and that he noted Irish Water would be paying the EPA's costs.
He ordered Irish Water to give €2,000 to the Merchant Quay Ireland which helps people affected by homelessness and drug abuse problems.
He adjourned the case until May 5 and said he would strike out the case if the money has been paid.