The Wanganui District Council has been issued with a formal warning by Horizons Regional Council, following more than a week of complaints about the smell from the council's wastewater treatment plant.
The plant was partially shut down early last week, after a large amount of protein waste was dumped into it through the Beach Rd pumping station. The strong smell from the malfunctioning plant could be smelled throughout Wanganui over the past week, but was particularly bad in Kaitoke and Marybank.
Horizons general manager of strategy and regulation, Nic Peet, said Horizons compliance staff had been visiting the plant daily and had received a number of complaints from the public.
Mr Peet said the council had not breached its consent but was in breach of permitted activities, one of the region-wide general rules.
He said the formal warning was a precursor to possible enforcement action, such as abatement notices.
But Mr Peet said Horizons was working constructively with council staff, who were trying to identify the cause of the odour and were also trying to fix it.
"While we know the district council is taking immediate action to address the problem, they are breaching the region's rules around air quality and, as the regulating authority, we need to act accordingly," he said.
Last week the plant's aerators were shut down and the bio-augmentation equipment was used to introduce specific odour treatment into the ponds. The council has also been manually de-sludging the ponds and a pre-plant treatment has been introduced at the pumping station in an effort to control the odour.
Dr Peet said the Horizons recognised it was a complex issue to fix.
He said he was expecting to be provided with an action plan from the council today, identifying additional short and long-term work to be undertaken at the plant.
Wanganui Mayor Annette Main said the formal warning was not unexpected.
"We have kept Horizons Regional Council staff fully appraised of what actions we are taking but unfortunately this kind of problem does not have an immediate quick-fix."
Ms Main said the council was taking the issue very seriously and doing all it could. "I am sorry for the people who have been affected by this and understand their concern and frustration," she said.
Meanwhile, Wanganui District Councillor Ray Stevens said work was continuing to find the business responsible for dumping the waste.