Fluoride independent inquiry 2022
In 2021, we stopped the fluoride facilities at the Te Mārua Water Treatment Plant in May and at the Gear Island Water Treatment Plant in November due to operational and health and safety issues, which meant we could not guarantee that we could add fluoride safely. At the time we didn’t tell anyone we did this, and we apologise for that, and the concern caused.
In March 2022, we announced that the fluoride facilities at Te Mārua and Gear Island had been stopped. However, we provided people with an incorrect date for when we stopped fluoridation at the plants, which we corrected the next day. Again, we acknowledge that this falls short of the expectations of our customers and communities, and we apologise for the concern caused.
Since then, we have worked at pace to safely restore fluoride at the Te Mārua and Gear Island Water Treatment plants. To do this we constructed two new fluoride facilities at Te Mārua and Gear Island and in September 2022 these facilities were operational and reliably fluoridating the drinking water within the Ministry of Health target range.
Independent Inquiry
To fully understand why the fluoride facilities were turned off at the plants and why our customers, community, Councils and our Board were not told of this in a timely and accurate manner, the Wellington Water Board commissioned an independent inquiry in March 2022.
The inquiry was undertaken by MartinJenkins and completed in late June 2022. The Board received and accepted all the inquiry’s recommendations in early July 2022 . Since then all the recommendations have been implemented.
In November 2022, the inquiry was formally closed out by the Board.
Inquiry findings
Inquiry recommendations
Implementing the recommendations
Local Government Official Information and Meetings Act Requests
We received a number of Local Government Official Information and Meetings Act requests for fluoride, and we have published our responses on our Official Information Act Responses page.
Timeline of key events

Fluoride updates and media releases
We have kept the public up to date throughout our work to restore fluoride at the Te Mārua and Gear Island Water Treatment Plants and to improve the reliability of fluoridation at the Wainuiomata and Waterloo Water Treatment Plants. This was done via weekly project updates.
We also issued a series of media releases for key announcements and milestones. See below for our media releases.
- Fluoride inquiry concluded, 18 Nov 2022
- New fluoride facilities now operating and fluoridating at the right levels, 29 Sep 2022
- Wellington Water to start testing new fluoride facilities, 29 Jul 2022
- Release of Wellington Water Fluoridation Inquiry, 8 Jul 2022
- Resumption of fluoridation at Te Mārua and Gear Island Water Treatment Plants, 3 Jun 2022
- Update on Wellington Water fluoridation inquiry, 27 May 2022
- Wellington Water updates on work to restore fluoride to Te Mārua and Gear Island Water Treatment Plants, 8 Apr 2022
- Scope and terms of reference set for Wellington Water fluoridation inquiry, 4 Apr 2022
- Wellington Water provides more detail on plan to get fluoride back in the drinking water in the Wellington metropolitan area, 18 Mar 2022
- Board of Wellington Water announces independent inquiry on fluoridation of drinking water, 17 Mar 2022
- Wellington’s drinking water fluoridation facilities are aging and in need of repair, 16 Mar 2022