Whanganui District Council has pleaded guilty to discharging human waste into a stream.
It is one of five prosecutions taken by the Manawatū Whanganui Regional Council – three have ended in guilty verdicts and two others are still pending.
The head of regulation for the regional council, Nic Peet, said the charge related to a discharge of wastewater from a pumping station into the Mowhanau Stream in January last year.
Landmeats New Zealand has been prosecuted for discharging wastewater into the Whanganui River in March last year.
Earlier this week, Le Poulet Fabuleux Limited was fined $57,000 in the Palmerston North District Court over wastewater from a Himatangi chicken-rearing operation.
Dr Peet said the discharge, detected in March last year, was draining into Lake Koputara, a habitat for threatened species.