Irish Water has pleaded guilty to breaking environmental laws in connection with wastewater contamination in Miltown Malbay in County Clare.
The Environmental Protection Agency is prosecuting the utility on 21 charges.
It was alleged Irish Water failed to provide safe and permanent access to all on-site sampling and monitoring points as required by its wastewater licence.
At the Dublin District Court today, the EPA solicitor told the court that progress had been made, and 16 charges would be withdrawn.
However, the court heard that Irish Water was pleading guilty to the five remaining counts.
The case has been adjourned until February 9th for an EPA inspector to give evidence, and for the defence to present a mitigation plea.