Odour from Whanganui's wastewater treatment plant due to sludge drying commissioning process

The processes in the de-watering room (pictured) and other parts of the sludge drying operation are being synchronised.

A strong odour in the Whanganui Airport area last week was likely due to a commissioning process at Whanganui's new wastewater treatment plant.

A Landguard Rd resident said there had been a smell "on and off" recently but it was particularly strong on Friday, August 3 and she thought it was coming from the treatment plant.

"It's quite bad and I've talked to people in Caius Ave across the river who have been smelling it lately too," the woman, who did not want to be named, said.

Whanganui District Council's infrastructure general manager Mark Hughes said a state-of-the-art sludge drying facility was being commissioned and last week work was being done to synchronise the thickening, de-watering and drying processes.

"We needed to open various parts of the plant and this may be when a smell was noticed," Hughes said.

"Occasionally during the biological commissioning stage of the project we had to temporarily open the covers on the ponds and other equipment and we were contacted by local people who said they had noticed some odour."

Biological commissioning of the plant was complete, Hughes said.

"This stage went very well and the resulting discharge is being treated to a high standard, exceeding consent requirements," he said.

"Once the sludge drying system is fully commissioned we do not expect there will be any smell from the plant. The plant has been designed with covers which should be effective in containing any odour."

Horizons Regional Council had not received any complaints about the smell last week or since the new treatment plant was commissioned, a spokeswoman said.

However, if anyone had a complaint they could call Horizons' pollution hotline on 0508 800 800.