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Wastewater treatment plants

The wastewater network carries a combination of residential and commercial (businesses) waste.

Wastewater contains 99% water and about 1% human and other waste.

Because the waste component contains many bacteria and viruses that could be harmful to human health, it’s important it is kept separate from the drinking water network. This is in accordance with the Health Act 1956.

All wastewater in metropolitan Wellington is carried along the wastewater network and treated at one of the four wastewater treatment plants, before being discharged out to sea, unlike the stormwater network which mostly flows straight out through streams and rivers before ending out at sea.

The metropolitan wastewater treatment plants are owned by Wellington City Council, Hutt City Council and Porirua City Council and are managed in accordance with the Resource Management Act 1991.

Moa Point Wastewater Treatment Plant

Porirua Wastewater Treatment Plant

Seaview Wastewater Treatment Plant

Western Wastewater Treatment Plant

Greytown Wastewater Treatment

Featherston Wastewater treatment plant

Lake Ferry Wastewater Treatment

Martinborough Wastewater Treatment Plant

Wellington Water/ Veolia Regional Wastewater Treatment Plant Services Review - October 2024

Wellington Water contracts Veolia to operate the wastewater treatment plants in the metropolitan Wellington region.

Together, we have been focusing on optimising the performance and operation of the plants to the best capability of the plants, within the funding that councils provided. We recognise that the plants and surrounding infrastructure are aging and have ongoing performance and compliance issues across the treatment plants.

In early 2024, prompted by recent compliance incidents and a request from our shareholders, Wellington Water and Veolia decided to commission an independent review into the causes of these issues, the actions taken in response, and our progress.

The review is now complete, and the report has identified opportunities for further performance improvements that would help bring the wastewater treatment plants closer towards full compliance and to deliver the best possible environmental outcomes.

Performance is one of the areas of concern. As a key action following the report, Veolia is proposing to reorganise its people into specialised roles around maintenance and operations. The aim is to allow clear definition of the roles and responsibilities necessary for success. 

Key documents: 

Independent review of wastewater treatment operations

News items on the independent review of wastewater treatment operations

3 / Feb / 2022

Wellington Water, as per the review timeline, has received the findings of the independent review into the operating model with Veolia - who is responsible for running all the wastewater treatment plants in the metropolitan Wellington region.

Wellington Water CEO, Colin Crampton, says that Wellington Water has accepted all 5 recommendations of the review. In addition, Wellington Water will continue its contract with Veolia on the condition that Veolia commits to and delivers on several significant improvements in its planning, delivery and resourcing.

“The review has highlighted that the management and operation of the wastewater treatment plants, and the ability to effectively to deliver public health and environmental objectives, has not been consistently achieved by Veolia,” says Mr Crampton.

“While Veolia is responsible for not meeting our expectations in their delivery of operations and maintenance of the four wastewater treatment plants, the contractual relationship, between Wellington Water and Veolia, has also played a role in their performance.

“The report also highlighted areas of improvement for us in the way we manage the contract and we will work to enhance our capability, systems and processes to allow better management of Veolia.”

“We remain committed to our role as a steward of water. This means we take care of water, our communities, and the environment. We take this responsibility seriously and will continue to strive for high standards of ourselves and our operator to meet the expectations of our communities, councils, and mana whenua.”

A steering group made up of representatives from Mana Whenua, Councils, Wellington Water and Veolia, has been established to oversee the implementation of the recommendations.

“We will keep our councils, community, and mana whenua informed as this work progresses,” says Mr Crampton.

The full independent review report and recommendations can be found on Wellington Water’s website.

22 / Nov / 2021

Wellington Water, in collaboration with its client councils, has finalised the Independent Panel, Steering Group and Terms of Reference for the review of the wastewater treatment plant operating model with Veolia.

The independent panel will be led by independent reviewers Roly Frost and Raveen Jaduram alongside Wellington Water’s Chief Advisor - Service Delivery, Euan Stitt.

A Steering Group, made up of Porirua City Council’s Deputy CEO/GM Infrastructure Andrew Dalziel, Ngati Toa’s Helmut Modlik, Veolia’s Alex Lagny and Wellington Water’s Chief Executive Colin Crampton, has also been established to provide input to the review process.

The review aims to identify actions and improvements to the wastewater treatment plant operating model that will ensure all the plants are operated in a professional, proactive, modern, fully compliant, and environmentally responsible way, and meet the expectations of Wellington Water, our communities, our client councils and Mana Whenua.

Wellington Water’s Chief Advisor - Service Delivery, Euan Stitt, says that the panel has ‘hit the ground running’ to get the review completed by the end of December 2021.

“We’ve already completed the information gathering stage and the initial round of interviews, with the draft report to be presented to the Wellington Water Board in late December.” Says Euan.

“The review will include an objective analysis of the current situation, performance and contract, delivery improvement recommendations, and an implementation plan. Once endorsed, we’ll move to implement the recommendations as soon as we can.”

21 / Oct / 2021

Wellington Water’s Chief Executive Colin Crampton has today announced an independent review of the organisation’s current operating model with Veolia, who is responsible for running all the wastewater treatment plants in the metropolitan Wellington region.

Mr Crampton says the review has been initiated following 10 warnings, infringement, and abatement notices across wastewater operations since May 2020, including a dry weather sludge discharge on 19 August from the Porirua Wastewater Treatment Plant that was identified by the community.

“Veolia did not notify us of this incident – they should have. This incident, and the ones before it, highlighted to us that action is needed now,” says Mr Crampton.

“Our role is to be a steward of water. This means we take care of water and the environment. We take this responsibility seriously and maintain high standards of ourselves and our operator to reduce the environmental impact of our operations.

Wellington Water has been working with Veolia to improve their performance over the last 12 months with the intent of reviewing the current operating model and arrangements at the end of the year.

“The public expects that wastewater, collected from houses and businesses, to be fully treated before it is put in the ocean. Unfortunately, these notices and incident are an indication that the wastewater treatment plants are not being operated to a standard that we would expect, which is why we’re initiating the review now,” says Mr Crampton.

Porirua mayor Anita Baker has welcomed the review, saying she is frustrated and disappointed to hear of Veolia’s stewardship at the Porirua Wastewater Treatment Plant.

“I welcome a vigorous review wholeheartedly and look forward to the findings. Porirua City Council and our community expect all our facilities to adhere to robust operating and reporting standards,” she says.

“I’d like to assure the Titahi Bay community and the Our Bay Our Say group that the Council has heard them, and these actions being taken we hope will lead to a safer and healthier Te Awarua-o-Porirua Harbour.”

In addition to the independent review, Wellington Water will also be looking at a more robust reporting framework for notifying the public of discharges and bypasses.

“We recognise that the public and our communities have a right to know when these incidents take place and we want to be more open and transparent about the performance of our wastewater treatment plants,” says Mr Crampton.

The independent review will be led by Roly Frost and Raveen Jaduram is expected to be completed by the end of December 2021. Wellington Water is working with its council owners on who will make up the governance of the panel. Details of this will be announced in the coming weeks.

Wellington Water will also ask the independent review panel to take a further look into the Porirua Wastewater Treatment Plant’s operations and performance. While the review is taking place, the treatment plant consent application will be paused.