Some ratepayers and councillors in Whanganui are questioning the cost of an odour-neutralising fence around the city's faulty wastewater plant.
The fence dispenses a chemical mist to control the smells which have plagued the city since late last year.
It costs between $1000 and $5000 a day to run.
The council met on Monday to discuss the fence and other solutions, but most of the discussion was closed to the public.
Whanganui's mayor, Annette Main, says the smell has improved in recent months but the council is keen to look at alternative options to the fence because of its high cost.
Councillor Rob Vinsen wants a temporary shut-down of the fence to gauge its effectiveness.
Resident Aromea Tamou-Samuel says the smell is now not as bad but she still notices it every day.
Another resident suggests the improvement is only because of the cooler weather.