Published 31/01/2025
Brief spike in fluoride levels at the Waterloo Treatment Plant resolved
As of January 31st, 2025, we completed a full review of the fluoride dosing system at Waterloo, and have identified and resolved the issue which resulted in the brief spike in fluoride dosing on Thursday 23 January 2025.
Following comprehensive monitoring and testing of the fluoride dosing levels at the plant, fluoride dosing has restarted on Friday 31 January, 2025 at 4:00 PM.
This brief spike caused no risk to public health, and our systems operated as designed to shut down the plant and alert operators to the issue.
There were two issues that contributed to the fluoride spike. The first related to the regular calibration of the monitoring equipment, the other to one of the dosing pumps. Following our review, we've adjusted the calibration process and modified monitoring software for the pump. Both of these steps reduce the risk of this issue occurring again. We have also closed the two closest cross connections to the plant, which will mean that if a similar issue occurs, the risk of impacted water reaching residents is reduced, and we will we have more time to stop the pump and drain the network.
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.