Safe to swim after sewage spill into Mowhanau Stream

No swimming signs have been removed after water testing found no contamination following sewage spills in the Mowhanau Stream at kai Iwi.

It's safe to go back in the water after raw sewage spilled into the Mowhanau Stream at Kai Iwi.

Unsafe-to-swim signs have been removed after testing by Horizons Regional Council gave the all-clear.

Two spillages happened, one on January 11 following a power failure and a second, unrelated spillage on January 22 as the result of a broken pipe.

Mark Hughes, infrastructure manager at the Whanganui District Council, told a council meeting on Tuesday, that Horizons had issued an abatement notice in order to carry out an investigation into the first discharge and that council would co-operate fully.

Council could potentially face penalties of $200,000 and be taken to the Environment Court, but Mr Hughes added he doubted that would happen.

The first spillage happened after a Powerco pole fuse blew causing wastewater to discharge into the stream from council's pumping station.

The fuse was repaired four hours after Powerco was told of the problem and the discharge stopped.

Water testing revealed high levels of contamination and a warning sign was erected. It was removed nine days later when water samples came back clear.

The sign went back up two days later after the second spillage which turned out to be less serious and has since been removed again.

Mr Hughes said a design fault was found with the Mowhanau pumping station and that non-return valves have now been installed.

Those would lessen the likelihood of further spillages by giving council staff more time to respond to any further incidents before wastewater was discharged into the stream.

Mayor Hamish McDouall noted that council staff had responded quickly to both incidents.