The change of owner for North Shore City's sewerage network when the Super City comes into being has supporters of Project Care worried that its bold but costly aims may not be met.
Long-time supporter John Shears, of Birkenhead, says the target was to reduce the city's average wet-weather overflows
from 12 a year to two a year by 2021.
The goal was called for by residents, disgusted by pollution of streets and beaches after heavy rain. Sewer manholes popped, pumping stations spilled filth into drains and warning signs went up at the beaches.
"I joined the residents in meetings with the council about Project Rosedale - to upgrade the city's treatment plant - and then the consultation over Project Care to upgrade the pipe network and put in holding tanks. North Shore City Council listened to what standard we wanted," Mr Shears said.
"And the project is working, because after the recent heavy rain, there were no discharges on to the beaches."
Project Care has cost $125 million, on top of the upgrade of the Rosedale plant ($100 million) and its new sea outfall ($117 million).
Householders' uniform annual sewage rate has risen from $329 to $480 in a decade.
But Mr Shears wants a legally binding commitment that Project Care progress will continue after November 1, when Watercare Services takes over the wastewater network.
Since November 2007, Watercare has had an appeal to the Environment Court about the council's application for resource consents for its network discharges.
"Watercare supplied only drinking water to the city, so what the hell was it to do with Watercare about our wastewater discharge consents?" said Mr Shears.
Accepting the Shore consent would set an expensive precedent for other networks in the region which had lower targets for overflows.
Getting all parties to approve the consents would give residents a formal assurance that the target would be met and works continue.
In January 2008, Mr Shears was accepted by the court as an interested party in the case.
He thought it the best way to keep pressure on to settle the dispute.
Watercare chief engineer Jim Hodges said the company was involved because it wanted to ensure consent conditions did not place undue constraints on its operations.
It was not suggesting the Project Care target should change.
