Implementation of community water fluoridation

Health (Fluoridation of Drinking Water) Amendment Act 2021

Some local authorities have been fluoridating the drinking water they supply for a number of years. Approximately half of New Zealanders have access to fluoridated drinking water.

Given its well established benefits for oral health, the Health Act 1956 was amended by the Health (Fluoridation of Drinking Water) Amendment Act 2021 to enable a nationally consistent approach to community water fluoridation.

The Health (Fluoridation of Drinking Water) Amendment enables the Director-General of Health to direct local authorities to add – or not to add – fluoride to a drinking water supply. Any local authority that receives a direction to fluoridate one of its drinking water supplies must take all practicable steps to ensure the optimal level of fluoride is present in that supply.

Local authorities may also choose to start fluoridating any drinking water supplies without being directed to by the Director-General. And any local authority that was fluoridating a drinking water supply before the amendments came into effect must continue to do so.

In deciding whether to make a direction to fluoridate, the Director-General is required to consider:

• scientific evidence on the effectiveness of adding fluoride to drinking water in reducing the prevalence and severity of dental decay
• whether the benefits of adding fluoride to drinking water outweigh the costs, taking into account the oral health and size of the community as well as the financial costs including ongoing management and monitoring.

If the Director-General were to issue directions to local authorities to fluoridate all drinking water supplies servicing populations over 500, it would result in over 80 percent of New Zealanders having access to fluoridated drinking water.

For further information on the legislative and legal framework for community water fluoridation, see:

• the Health (Fluoridation of Drinking Water) Amendment Act 2021
• documents related to the development of the Amendment Act
• 2018 Supreme Court judgment – in accordance with the respective views of O’Regan and Ellen France J and William Young J, the Court found that the South Taranaki District Council has legal authority to fluoridate the water supplies in Patea and Waverley and that power is not constrained by s 11 of the Bill of Rights Act.

Directions to fluoridate 14 local authorities

The Director-General of Health has issued 14 directions to local authorities to fluoridate community water supplies. This follows a process as described in the Health Act 1956.

The 14 local authorities that have received directions are:

Manatū Hauora is supporting local authorities that received a direction in July 2022 with funding for capital works. The compliance dates vary and are based on information provided by local authorities.

For further details, see the information provided to the Director-General to inform decision-making on these drinking water supplies.

Will further directions to fluoridate drinking water be issued?

In November 2022 the Director-General wrote to 27 local authorities to advise that they are being actively considered for a direction to fluoridate in relation to one or more of their drinking water supplies.

These water supplies remain under active consideration, however the Director-General is taking further time. This is to allow consideration of the impact of several wider factors including reform across the water services sector, and service delivery pressures across the local government sector.

Monitoring drinking water fluoridation levels in New Zealand

Water treatment plants are monitored regularly to ensure fluoride concentrations do not exceed the maximum acceptable value set out in the Water Services (Drinking Water Standards for New Zealand) Regulations 2022 (ie, 1.5 mg per litre). Taumata Arowai – the water services regulator – monitors compliance with the Drinking Water Standards, including for fluoride. Any exceedances must be reported to Taumata Arowai.

The Ministry is developing a monitoring process to ensure fluoride levels across New Zealand remain within the optimum range for oral health benefits (ie, 0.7–1.0 mg per litre).