Big water task ahead

Strategic project manager Martin O’Malley at the Frankton  wastewater maturation pond.
Strategic project manager Martin O’Malley at the Frankton wastewater maturation pond.

Queenstown Lakes District Council is not quite in the poo yet but needs a multimillion dollar solution to a once-in-a-generation infrastructure upgrade for the resort's sewage and wastewater treatment.

Waste disposal by the council at the Frankton treatment ponds is occasionally in breach of consents, the cost of fixing the system is in the tens of millions of dollars and an existing discharge consent into the Shotover River expires next year.

The council needs to solve a sticky problem. The sewage treatment ponds at Frankton built in the 1970s need to be upgraded by 2014 or replaced entirely with a new system to cope with increased infrastructure demand and a growing population.

Yesterday, Queenstown Lakes District councillors met to discuss the latest Project Shotover report.

Strategic project manager Martin O'Malley told the Mirror the first stage of the works would involve upgrading the quality of the water discharged into the Shotover River.

The ponds produce slurry-like water and in the long term the council aims to pipe wastewater directly into the ground in the Shotover delta and build a mechanical plant to replace the ponds.

Nitrogen levels need to be reduced, although the chemical level and faecal matter content during summer is low compared with winter, when the ponds freeze, preventing aeration.

"This is as good as the ponds will treat, " Mr O'Malley said.

"We acknowledge we have to upgrade that.

"The true test is winter. "That's a big problem. In the 10-year plan the first thing we do is upgrade the discharge (to the Shotover)."

By 2015, the council aims to improve the discharge quality, pipe wastewater into the delta underground by 2021 and complete a full upgrade by 2025.

Meanwhile, Fulton Hogan has been awarded a $2.5 million contract to upgrade the screening plant below Glenda Dr, where the resort's sewage solids are separated for landfill and the wastewater sent to the ponds.

For the overall staged upgrade, the council received 17 submissions proposing solutions, at a cost of about $35 million - comprising $27.12m for a treatment plant upgrade by 2015 and $8.m for the land disposal in the delta.

Operationally, a new plant will cost $2.15m a year compared with the existing $400,000 a year and upgrading will be funded by developer contributions and rates.

For Queenstown Lakes the new plant is likely to be the single largest infrastructure cost for decades.

The current long-term funding earmarked $16.9m for construction, $4.2m for construction and commissioning, and $5.4m for design.

The council is also investigating interim options because of the prohibitive full upgrade cost, which could involve a medium-term consent which would apply for 15 years.

Meanwhile, sludge removed from the ponds is dried along the banks of the Shotover.

About 10,000 tonnes of wet sludge was dried and should be sent to landfill before winter.

Councillors approved a recommendation to apply for staged resource consents as the project progresses.

The Mirror