A member of the Wanganui wastewater working party, which guided the development of the city's wastewater treatment regime, says an emergency discharge from the treatment ponds is the quickest and best cure for the city's odour woes.
Ross Mitchell-Anyon, a former district councillor, was a member of the working party which in 1990 brought together diverse groups to consider best options for treating both the city's residential and industrial waste.
"For the mayor and councillors to say the odour isn't a health risk is ridiculous. Anything that makes you feel sick is a health risk and has to be considered as such," Mr Mitchell-Anyon told the Chronicle.
He said the stench was a serious matter but believed a solution lay in the council seeking permission for an emergency discharge from the treatment ponds. This would clear out the built-up sludge in the ponds and let the system get back to normal.
He said he was certain the consents under which the ponds currently operated allowed for such emergency discharges through the South Beach marine outfall.
"There may be some fats pushed up on to beaches south of Wanganui, but they would break down quickly enough. But the point is no one should have to put up with this sort of stench.
"The effect on the environment would be negligible, even if it happened over a few weeks or a couple of months, but the effect on the community would be enormous."
Mr Mitchell-Anyon, who lives in Gonville, said there had been nights when he said he felt as if he was sleeping with his head "down a drain".
He said the working party got buy-in from groups including local iwi, the Department of Conservation, health authorities as well as the council.
He said there was some consensus that the best way of taking care of both community and industrial waste was a split waste option, but it was abandoned by the district council. That would have seen the city's major wet industry - the Affco meat plant - set up its own pre-treatment system, which would have by-passed the need to use the city's treatment ponds.
"Affco is by far the biggest of those wet industries, and its discharges carry vast amounts of suspended solids and fats," he said.
"The wastewater working party recommended this primary treatment solution, and Affco had considered paying for it themselves, but that scheme (called 2A) never went ahead. I'm frustrated the split system was abandoned, because it made all the sense in the world," Mr Mitchell-Anyon said.
He said he clearly remembers the working party being told that allowing industrial wastes to be put into the city's treatment plant "would come back and bite us on the bum".
"We had to future-proof the plant, and by removing industrial wastes we took out the risk of any major sludge problem."