The Wellington wastewater treatment plant at the centre of the capital’s sewage spill has a history of performance failures, non-compliance, and infringement notices stretching back years.
Seventy million litres of raw sewage are currently leaking into Wellington’s south coast each day, with beaches potentially off limits for months during the peak of summer, as faeces and toilet paper can be seen swirling in the surf.
The issue at the city’s Moa Point Wastewater Treatment plant was discovered early yesterday morning, with a suspected blockage in the long outfall pipe causing the facility to flood with sewage.
Now, sewage is being discharged untreated from a short pipe on to the beach, meaning what Wellingtonians flush down their toilets is ending up just five metres offshore on the South Coast.
Asked directly by Ryan Bridge this morning whether he had been made aware of any potential issues at the plant since being elected mayor, Andrew Little said he had not.
“There’s been nothing indicated to me in the time I’ve been mayor or even before that that is a plant that’s at risk,” Little said.
“I don’t know whether what happened with the treatment plant is a freak accident or what, we won’t know until we do the investigation.”
But reports into Wellington Water’s facilities show long-standing challenges at Moa Point, although it is not yet clear whether those issues contributed to this week’s equipment failure.
Month-by-month compliance reporting shows the plant has never been fully compliant or without issue for a single month since August 2023.
Looking back earlier, the facility was found to have “not met compliance requirements or performed in an acceptable manner” in a report from December 2021.
The issues highlighted at the time relate to effluent non-compliance, sludge pipeline failures, non-compliant air discharge levels, too high levels of suspended solids in wastewater, and blockages in air flow, among others.
The report slated contractor Veolia, which is responsible for running the plant, for “its failure to meet the expectations of Wellington Water in its delivery of operations”.
“The dysfunctional culture in the contractual environment has played a role in the WWTP [Wastewater Treatment Plants] performance,” the report said.
Both parties had worked together to try tackle the situation, but without success.
“In the relatively short period the contract has been in effect, Wellington Water has raised with Veolia concerns about non-compliance, health and safety, asset failures, response times and management. It has commissioned numerous improvement initiatives and reviews, but there is little evidence these have had any positive impact”.
Veolia said its staff viewed their treatment by Wellington Water as that of a “master-slave relationship” which impacted their performance.
Contractors for the multinational company also argued there have been too many reviews, which took them away from their key operations functions.
Further issues were identified in papers put before the Wellington Water Committee in December last year.
“Moa Point is non-compliant for suspended solids,” the paper said, and achieving consistent compliance would take “several years”.
Throughout 2024 and 2025, enforcement actions including an abatement notice and two infringement notices were issued against the Moa Point facility.
“We have been on a joint journey with Veolia to improve the management and operations of the plants,” the report said.
Veolia and Wellington Water have been contacted for comment.
The current “catastrophic failure” comes as remedial work had been under way on the facility.
That work caused it to run at reduced treatment capacity, something which had proved problematic for the facility’s performance.
In October last year, seven unconsented wastewater discharges were reported due to the plant’s reduced treatment capacity.
Little has called the issue an “environmental disaster”.
“It beggars belief that in this day and age that there could be such a catastrophic failure,” he said.
Wellington Water will soon be replaced by a new water entity, Tiaki Wai, as part of the Government’s water reforms.
Many of Wellington Water’s current staff and existing contracts will transfer to the new entity.
Ethan Manera is a Wellington-based journalist covering Wellington issues, local politics and business in the capital. He can be emailed at ethan.manera@nzme.co.nz.