Wanganui District Council will hold a public meeting with residents in the Kaitoke area about the smell from the wastewater treatment plant.
Infrastructure manager Mark Hughes said the council had had a major setback in its treatment improvement programme for the plant.
"Over the weekend the plant suffered from a major intake of protein material through the Beach Rd pumping station. It is not known where this material originated from. This has caused a huge decrease in oxygen levels in the plant, halted the bioaugmentation digestion process and given rise to excessive odours.
"Today the plant has been partially shut down until the protein compounds can be treated and limited aeration and bioaugmentation recommenced.
"The bioaugmentation programmes for treating the solids and odours have, up until this time, been working well and as planned, but unfortunately this incident has set us back a couple of months. Council is extremely disappointed with this unfortunate and unnecessary setback."
Mayor Annette Main said council had received calls and emails about this and other odours over the weekend. Some were not due to the wastewater treatment plant but reports suggested they may have been due to industrial activity around the Heads Rd area.
"I cannot promise a speedy solution to the current problems with the wastewater plant, but I can assure those affected that this is being treated as a very high priority. We will provide as much information as possible as progress is made on the problem."
Several residents in the Kaitoke area said the smell was so bad that they had to seal up their houses, and washing hanging on the line became tainted with it.
Grant Gaisford said the smell at his house on Kaitoke Rd was "rancid" and said his throat became sore because of it.
"When we brought the washing in off the line, everything had that smell. We have a major problem out here, and something needs to be done about it," Mr Gaisford said.
Barbara Hackett from Marybank said she had to virtually seal up her house over the weekend to try and keep the smell out.
She said what irritated her most was that the houses at Marybank were not connected to the city sewerage scheme.
Mrs Hackett was also angry that when she contacted the council to complain about the smell, she was told she needed to talk to Horizons Regional Council.
"What are they going to do about it? It's the council's responsibility."
Councillor Ray Stevens, chairman of the council's infrastructure and property committee, said he understood residents' concerns and wanted to work with them to fix the problem.
"Obviously, we're not doing 100 per cent and we need to deal with that."
Mr Stevens said he wanted to hold a public meeting with the affected residents.
Ms Main agreed, saying that as far as she knew there had never been a problem with the smell for Kaitoke and Marybank residents before.
No date for the meeting has been set.