Auckland

Water in the Auckland region is managed by WaterCare, a limited liability company. They have provided answers to these questions about fluoridation.

Fluoride is currently added at main treatment plants supplying metropolitan Auckland.

In 2022, we were directed by the Director-General to install fluoride dosing systems at our Onehunga Water Treatment Plant by 30 June 2024. We were also directed to upgrade our three Waiuku plants and fluoridate the community’s water supply by 30 June 2026.

Fluoride is not currently added at our non-metropolitan water treatment plants, serving communities in Waiuku, Bombay, Huia Village, Wellsford, Warkworth, Snells-Algies, Helensville and Muriwai. In the past, the decision on whether to fluoridate water supplies rested with Auckland’s legacy councils. We retained the position of legacy councils when we became responsible for the region’s water and wastewater services in 2010.

Watercare’s current role regarding fluoridation of drinking water supply is to undertake and maintain compliant fluoridation system operations.

 Watercare uses hydrofluorosilicic acid (HFA) as the fluoridating agent which is one of the three approved fluoridating agents as per the Code of Practice for the Fluoridation of Drinking-Water Supplies in New Zealand. The other reasons we use the HFA are as follows:
• chemical availability and security of supply – it is produced in New Zealand and readily available;
• the manufacturer has quality management systems in place to ensure chemical consistency and quality; and
• Watercare’s experience and practices associated with the use of HFA.

At water treatment plants where we dose the water with fluoride, it is added as one of the final steps before the water leaves the plant. It is dosed at a specified concentration to maintain fluoride level between 0.7 and 1.0 mg/L as recommended by the Ministry of Health so there is no risk of dosing a more concentrated solution.
The maximum acceptable value of fluoride is 1.5 mg/L, as set by the Drinking Water Standards for New Zealand 2022 (DWSNZ). Watercare has strict control measures in place to ensure that this is not exceeded.

Auckland’s drinking water undergoes rigorous testing to make sure it is safe to drink.
Our treatment plants use continuous online instruments to monitor fluoride levels in the treated water. Alarms are triggered and dosing stops if the fluoride concentration deviates from the control limits.
We also test our treated water every week at the Watercare Laboratory to ensure fluoride levels are in the recommended range. These results are published on our website each month and are also reported in our annual water quality reports (under Water quality reports section).

Watercare maintains online monitoring instrumentation in conjunction with the supplier specifications.
Weekly laboratory samples are tested by the Watercare Laboratory, which is registered with Taumata Arowai and internationally accredited, this means the testing is comprehensive and reliable.

• Wastewater from our wastewater treatment plants: After treatment, wastewater from our wastewater treatment plants is discharged to the environment (land, rivers or sea) in accordance with our wastewater discharge consents. Sludge from our wastewater treatment plants, containing low levels of fluoride, is discharged into consented sites to land.
• Wastewater that is a byproduct from our water treatment processes: Wastewater containing low levels of fluoride from our water treatment plants is discharged into either the wastewater network or consented stormwater discharge points.

We do not discharge concentrated fluoride onto consented sites to land. The concentrated fluoride is stored in bunded areas. Bunding is essentially a containment system and the fluoride chemical itself and it does not go to landfills. Instead it is added to the water, as one of the final steps of the process, as described above.

There is no requirement to hold a resource consent for the discharge of water containing fluoride at the levels found in the wastewater discharged from our wastewater treatment plants, nor from water discharged from the water network.

Some of our water treatment plants have resource consents that contain limits for fluoride. These resource consents are for the disposal of the by-product of the water treatment process, and the resource consents listed allow for the discharge of fluoride in line with the consent.
A list of the relevant sections of the consents that permit the discharge of fluoride from our water treatment plant processes is set out below.

No. Fluoridation of Community Water Supplies is not an activity controlled by the Resource Management Act and as such it does not require a resource consent. Fluoridation if carried out must comply with the requirements of the Water Services Act 2021, the Drinking Water Quality Assurance Rules 2022 & Water Services (Drinking Water Standards for New Zealand) Regulations 2022.

As at 30 June 2024, our fluoride chemical cost was ~$368k. The cost of fluoridating water supplies is made up of capital, maintenance and fluoride costs.

The cost of implementing fluoridation of water supplies differs by plant size, and the investment relative to the production capacity. Capital and maintenance costs also vary with the number of plants servicing the population; i.e. a higher number of treatment plants increases the average costs.

Routine sampling of fluoride is carried out weekly and costs $6,200 per annum for our six Water Treatment Plants that currently fluoridate.

Watercare is withholding the cost per tonne of hydrofluorosilicic acid in order to protect the commercial position of our supplier (s7(2)(b)(ii) of LGOIMA).

Answer not currently provided.