D Day in city's war on stench

International wastewater experts will be in Wanganui today to start the process of deciding whether the city's smelly wastewater treatment plant can be saved.

The Wanganui District Council held an extraordinary meeting yesterday afternoon and agreed unanimously to commission a report on the future of the plant from Cardno BTO, an international group of specialists in wastewater treatment and process engineering.

The city has been plagued by a stench from the plant since early December, when an unidentified local industry dumped a large amount of solid waste into it. The council has since revealed that the plant, which is five years old, was poorly designed and has never functioned properly.

The council received a report on the issues surrounding the plant from infrastructure manager Mark Hughes, who was also present at the meeting to answer questions from councillors.

Mr Hughes said Cardno BTO was approached by the council in November 2011 to review the wastewater treatment plant and prepare a 10-year upgrade plan.

He said by that stage the council had not met the requirements of its resource consent for any year since the plant opened, odour complaints were still being received, and operating costs for the plant - mainly for electricity - were much higher than expected.

In response to a question from Councillor Michael Laws, Mr Hughes said he understood that councillors had never been made aware of Cardno BTO's report.

Mr Hughes told councillors there were four possible designs for the council's wastewater treatment plant but that the council and its design partner, MWH, had chosen none of them.

"It appeared to MWH and

D-Day in war on stench

that plagues our city

CRUNCH TIME: Wanganui District Council's infrastructure manager, Mark Hughes, at yesterday's extraordinary council meeting to discuss the future of the wastewater treatment plant.PHOTO/STUART MUNRO council staff that it should be possible to identify the most desirable features of all the options and put these together," he said.

"This design was untried until we tried it."

Mr Hughes said the system did not work because it attempted to put aerated and non-aerated layers of waste in the one pond. A further problem was that waste was not being adequately treated by the system.

He said the council needed to find out whether the problems with the plant could ever be fixed.

"That's what we will be asking Cardno BTO to find out. We need to examine if the plant can ever be made compliant, and if so, how."

He said the timeframe for that was three months. The cost would come from within existing wastewater budgets.

The recommendation was that the council commission Cardno BTO to provide a future options report that includes:

Any additional measures that can be taken to address odour

To determine whether it is viable to continue with the plant

If viable, which options to achieve satisfactory performance are available for completion over the next two years

If not viable, then establish which type of plant would be suitable for Wanganui's waste

And that the report is peer reviewed by an agency that is independent of the wastewater treatment plant project.

The recommendation was moved unanimously.