Drinking water

All New Zealanders deserve safe, reliable, and affordable water services that support good health and sustainable environmental outcomes.

Taumata Arowai is an independent water services regulator for Aotearoa New Zealand.

Taumata Arowai became fully operational as the drinking water regulator when the Water Services Act 2021 came into effect on 15 November 2021. Part 2A (Drinking Water) of the Health Act 1956 was repealed from this date. 

Following public consultation Taumata Arowai have published new drinking water standards which came into effect on 14 November 2022.

Drinking Water Standards — Taumata Arowai (external link)

The Ministry of Health will remain as the organisation in charge of drinking water policy and will work closely with Taumata Arowai.

Water services insights and performance — Taumata Arowai (external link)

Nitrate (NO₃) is made up of nitrogen and oxygen.

There are several ways that people can consume nitrate. Drinking water is one of these. Typical sources of nitrate in the environment include:

• fertilisers
• animal waste, particularly in areas of intensified farming 
• unreticulated sewage disposal systems
• industrial and food processing waste.

Nitrate is highly soluble in water, which allows it to move easily through the soil and leach into groundwater and drinking water sources.

Nitrate in drinking water 

The New Zealand Drinking Water Standards set out the maximum number of nitrate and other substances that are acceptable in drinking water. These maximum amounts are known as the "maximum acceptable value" or "MAV".

Water Services (Drinking Water Standards for New Zealand) Regulations 2022 — New Zealand Legislation (external link)

Your local water provider and the Water Services Authority | Taumata Arowai are responsible for ensuring nitrate and other substances in drinking water are below the MAV. For further information around testing refer to the Taumata Arowai website. 

Maximum amount of nitrate that is acceptable in drinking water — Taumata Arowai (external link)

Health effects of nitrate in drinking water

High levels of nitrates in drinking water can reduce the blood's ability to carry oxygen. This can lead to a rare but serious condition in babies called "Blue Baby Syndrome" (methaemoglobinaemia).

This condition affects infants under 6 months old and unborn babies. It occurs when bacteria in the gut convert nitrate into nitrite, which then binds to fetal haemoglobin, blocking oxygen from circulating properly. 

Symptoms include:

• a bluish tinge around the mouth, hands and feet
• breathing difficulties in severe cases.

Though the condition is rare in New Zealand, it is still important for families — especially those using private or bore water — to be aware of the risks. 

Those most at risk of methaemoglobinaemia

High risk groups include:

• bottle fed babies less than 6 months old
• babies given boiled water
• pregnant women.

Adults with specific rare metabolic disorders (deficiency of glucose-6-phosphate dehydrogenase or methaemoglobin reductase) may also be at risk.

Exclusively breastfed babies are not at risk because nitrate/nitrite does not pass into breast milk.

People in high risk groups should not consume water that is high in nitrate.

If you are concerned about your health, talk to your midwife or healthcare provider, or call Healthline for free anytime on 0800 611 116

Check through the following information on how to be ready and respond in a natural disaster. 

Protecting your health before and after a natural disaster — Health Information and Services (external link)