Published 23/01/2025
Brief spike in fluoride levels at the Waterloo Water Treatment Plant no cause for public health concerns
Wellington Water is working to identify the cause of a brief spike in the fluoride levels at Waterloo Treatment Plant.
“Our treatment plants are all closely monitored and equipped with sensors which alert us to any issues. This afternoon, our system analysers picked up a spike in fluoride levels between 12.07pm and 12.25pm (18 minutes) where the treated water at the plant was between 1.5 and 1.8ppm (parts per million). A small volume of water that contained elevated levels of fluoride was delivered to some suburbs in Hutt central.” says Pat Dougherty, Wellington Water CE.
“This exceeded the Ministry of Health's Maximum Acceptable Value of 1.5ppm, which is set based on long-term exposure. With a spike this short, we can confirm that there is no risk to public health. To put it in perspective, some popular teas contain around twice as much fluoride as the levels experienced during this spike – and adult toothpastes typically contain 1,000 to 1,500ppm.”
Even though there is no risk to public health, Wellington Water is running a full investigation into the cause of the spike.
“To ensure the safety of our communities, our treatment plants are designed to shut down if any issues occur and to quickly alert our treatment plant crews to any issues – so it’s really positive to see all our controls working as they should” adds Pat.
“The sensors at the Waterloo treatment plant detected the spike and automatically shut down the pump and alerted the operators, which is the system doing what it’s meant to do. Once alerted our operators moved quickly to isolate the affected area of the plant to prevent further drinking water flowing through into the network. We then drained the water from the affected pipes.”
As a result of this incident, our crews have turned off the fluoride facility, and it will remain off until the cause of the issue has been identified and resolved. As this fluoride spike has exceeded the levels allowed by Drinking Water standards, as per standard procedure Wellington Water has notified Hutt City Council, Taumata Arowai and Regional Public Health.
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.