Published 13/11/2025
Wellington Water managing odour risk following operational incident at Seaview Wastewater Treatment Plant
Following an error with routine operational maintenance at the Seaview Wastewater Treatment Plant (WWTP) undertaken by our contractor Veolia, Wellington Water is alerting the community to the strong possibility of increased odour.
The mistake has been corrected, however the biological process at the plant has become unbalanced. The biological process treats wastewater, and when it is healthy and balanced the risk of related odour is very low. However when it is unbalanced, it can cause higher levels of odour.
To manage this risk, we will begin sludge trucking as soon as possible. By removing the wet sludge from the plant, we give the biological process the best possible chance of becoming stable again. However, it’s important that the local community are aware and they should expect increased odour from both the sludge trucking and the plant.
We are closely monitoring the situation and making sure Veolia is taking all possible action to reduce the impact on the community.
“Wellington Water deeply regrets any impact felt by the community, and wholeheartedly apologises,” says Pat Dougherty, Wellington Water CE. “This is completely unacceptable. We acknowledge that it was around the same time last year that we had issues with odour from the plant and we are gutted that this has happened yet again at the start of summer.
“We are holding Veolia firmly to account. While we are focused on reducing the impact and duration of any odour, we are also committed to ensuring this doesn’t happen again. We have asked Veolia to provide a robust plan so we can give our community confidence moving forward.”
We will continue to keep the community informed and will issue further communications once we know the likely extent of the impact to the biological process, and timeframe of the odour impact.
We will provide information via our Seaview WWTP Interested Parties list, on our website, and via social media. To sign up for the Interested Parties list, please email customer.notifications@wellingtonwater.co.nz.
Editor notes
Wellington Water is owned and fully funded by Wellington City Council, Hutt City Council, Porirua City Council, and Upper Hutt City Council, Greater Wellington Regional Council and South Wairarapa District Council. All six councils are equal shareholders.
Our councils own the water infrastructure in the region, and they task us to manage the infrastructure and deliver water services to our communities.
Wellington Water is governed by a Board of Directors. The Board and our organisation receive overall leadership and direction from the Wellington Water Committee, which are also responsible for appointing members to the Board.
The Wellington Water Committee is made up of representatives from our council owners and mana whenua.