RDC was fined for an illegal discharge of untreated human effluent in Taihape into the Hautapu Stream, following a number of complaints from the public, Peet said.
When RDC heard about the complaints the Taihape Pump Station was checked, and it was clear the discharge was not from there. A further search found a rogue pipe connection to a maintenance hole. It was not in building plans.
The overflow pipe was blocked, which ended the discharge, Rangitīkei Mayor Andy Watson said. The discharge would have been irregular, infrequent and mainly during high stream flows.
It did not happen in the swimming season but the small volumes over an extended period did pose a potential risk to human health.
The council is upgrading the Taihape Pump Station and its wastewater treatment plant this financial year. Its level of service will be better and environmental risk will lessen.
The council is remorseful about the discharge, and will take part in a restorative justice process with both Horizons and tāngata whenua, Watson said.
Ninety per cent of its fine will be paid to Horizons.
"Once ratepayer costs have been recovered, any remaining funds will be used to enhance the stream in conjunction with the community," Peet said.
Coles Transport was fined for the failure of a large open-air effluent pond which serviced a truck wash-down. The failure resulted in a discharge over a cliff and into the Rangitīkei River for a period of months.
"Horizons acknowledges that both parties cooperated in the investigations and entered early guilty pleas. In doing so, they have recognised their wrongdoing and assisted with saving considerable ratepayer costs."
Horizons takes its role as an environmental regulator seriously, Peet said. It has an active compliance monitoring programme and also responds to pollution incidents.
"Members of our community are encouraged to report any environmental incidents to our 24-hour Pollution Hotline on 0508 800 800."