Lesser Akaroa wastewater treatment possible under proposed new standards

Wednesday, 16 April 2025

A sign outside the existing Akaroa wastewater plant warns of downstream effects.

Christchurch could build a lesser and cheaper wastewater treatment plant in Akaroa than it has planned, councillors were told on Wednesday.

“In terms of Akaroa … we could have a lower level of treatment if we choose,” a staffer told councillors.

They were discussing Christchurch City Council’s response to new national standards for wastewater treatment proposed by the water regulator, Taumata Arowai.

No councillor endorsed a lesser Akaroa scheme and neither did staff.

The existing plant Akaroa wastewater plant.

But there were enough gaps in the proposed standards that it was unclear if the council could build an Akaroa scheme that exceeded the national standards at all.

'No clear direction is provided in the standards regarding [councils] electively treating [wastewater] to a higher standard than those set out in the standard,“ read the council’s draft response to the regulator. “It needs to be clear if this will be permitted or not.'

That said, the Commerce Commission indicated last week it would view schemes only with an “economic lens”, a staffer said.

A better-than-necessary scheme would cost more and the council would have to consult residents before spending the extra money, councillors were told.

The legislation would make it impossible for councils to impose more stringent consent conditions on private companies or farmers, for example, than set out by the proposed standards.

Sewage treatment in Akaroa has bedevilled the council and harbour residents for years. The latest proposal was put on hold in March because of the very standards that could make a lesser scheme possible, the council said.

Opponents argued the latest scheme was deeply flawed.

The National Wastewater Environmental Performance Standards arise from proposed legislation under the Coalition Government’s Local Water Done Well policies.

Staff and councillors had other concerns as well. The Local Government (Water Services) Bill removes Mana o te Wai - essentially Māori cultural understandings and objectives - from the water regulator’s objectives.

The council wanted “co-design and mātauranga Māori integration in future standards”.

Odours from wastewater treatment - “a high-profile community issue” - should not be deferred to a future phase of reform, the council heard.

Meanwhile, emerging contaminants such as forever chemicals, microplastics pharmaceuticals were not included in the proposed standard.