Wellington’s waste water treatment plants in bad shape

Saturday, 16 March 2024

The Seaview Waste Water Treatment Plant in Lower Hutt has had ongoing odour issues. It was one of a number of plants across the region that Wellington Water says need upgrading.

The region’s waste water treatment plants are in a poor state and Wellington Water warns they pose a bigger threat to the environment than the current water shortage.

A range of Wellington Water officers and board chair Nick Leggett delivered the bad news to a meeting of the councils’ water committee on Friday.

Wellington’s Moa Point, the Seaview Waste Water Treatment Plant and the South Wairarapa Council’s three treatment plants all need upgrading. Moa Point is nearing the end of its life and has a risk level listed as “high to extreme”.

As with the fresh water drinking pipes, the poor state of the treatment plants is a result of chronic underinvestment in maintenance.

Leggett said Wellington Water needed to spend $30 billion over the next 30 years and had asked for $7.6b over the next 10 years from councils across the region.

It had received less than half the money it needed to make progress on upgrading three waters infrastructure.

He also noted that the councils had on-going concerns about the water shortage and how it would be handled in future years.

Wellington Water says the state of waste water treatment plants has been overlooked due to the focus on leaks.

The board “had been straight up” in stating how much it needed to rectify the current issues facing the region.

He warned that the councils’ underinvestment created a range of “risks” the region would have to deal with.

Wellington Water would not be able to renew pipes at the required rate to replace the ones that are failing.

“The network would continue to age and we would continue to get more leaks and the cost of repairing those leaks would continue to rise. We can’t sugar coat that.“

Wellington Water boss Tonia Haskell is looking at the state of waste water treatment plans across the region.

There would also be ongoing issues with waste treatment plants, Leggett said.

Underinvestment also meant Wellington Water would be unable to achieve strategic objectives, including improving water quality and planning for growth in housing.

Health warning signs posted at Tarakena Bay near Moa Point in Wellington after sewage was discharged into the bay. (File Pic)

Chief executive Tonia Haskell said the regulatory rules around treatment plants were getting tougher and the regional council was taking an increasingly close interest in their treatment plants.

“They are holding us to account on the performance of our waste water treatment plants. That will probably be as big a challenge, if not more, as our acute water shortage, as we head into winter. Those plants are old and need more investment and they need nursing.”

Moa Point’s high risk level is due to the failure to fund much needed maintenance, including electrical and control systems. Haskell said it was reaching the end of its life.

Group manager Julie Alexander said that while Wellington Water was getting most of the money it had asked for to upgrade the plants over the next 10 years, much of the money would be spent in the last seven years of their 10 year plan.

That meant the plants would continue to age and pose a risk to the region.

Wellington Water chair Campbell Barry said that while everybody understood how serious the issues of leaks was, the threat posed by waste water treatment plants had flown under the radar.

“I don’t think that we have an understanding of the risk when it comes to waste water treatment plants, which, from an environmental point of view, would have a far greater impact.”

Haskell said staff planned to examine the issues around treatment plants as a “winter challenge” and would report back with potential solutions.

Earlier in the meeting Porirua mayor Anita Baker said that a broken pipe, earlier this week, had resulted in raw sewage spilling into Porirua waterways.