Hamilton City Council and one of its staff are being prosecuted over a sewage sludge spill at the Pukete wastewater treatment plant last July.
The spill resulted in about 90,000 litres of partially treated sewage sludge entering the Waikato River.
The council and the staff member have each been charged in the Hamilton District Court by Waikato Regional Council with a discharge of sewage in breach of the Resource Management Act.
No court date has yet been set for the hearing of the charges.
“The decision to lay the charges has been made by a group of senior regional council staff after careful consideration of the results of an investigation into the circumstances surrounding the spill,” said investigations and complaints manager Patrick Lynch.