Fluoridation of Ōamaru's water supply begins again on Thursday (23 January).

Despite strong opposition, fluoridation of the water supply began in July last year. It was paused early in October after testing indicated an error in the dosing calculation and the analyser which reported the fluoridation level in the water.

However the fluoridation levels remained within the acceptable values for drinking water during this time, Waitaki District Council infrastructure manager Joshua Rendell says.

The testing in October indicated levels of 1.07mg/L post-reservoir and 1.08mg/L at South Hill.

The council targets 0.8 mg/L for fluoridation, following the Director General of Health’s directive to fluoridate between 0.7 and 1.0 mg/L. 

The maximum acceptable level of fluoride in drinking water is set at 1.5mg/L in the Water Services (Drinking Water Standards for New Zealand) Regulations 2022.

Council Water Services and commissioning contractors Filtec have been working to recalibrate the dosing equipment and analyser to ensure the targeted level.

Daily testing will be done in the network until fluoride is present in the supply, Joshua says.

From then, weekly testing of the supply will be carried out both at the point of fluoridation and elsewhere on the network, to ensure the water is fluoridated between 0.7 and 1.0 mg/L, with the target level set at 0.8.

The Director-General of Health Diana Safarti completed her Bill of Rights analysis relating to the directives to fluoridate in December 2024, and all cases brought before the High Court have confirmed the directives are lawful, he says.

All further enquiries should be directed to the Ministry of Health.