Private drinking water supplies

Under the Water Services Act 2021 (the WSA), if you own or operate a water supply that provides drinking water to more than one household, then you are considered a drinking water supplier. All drinking water suppliers have a duty of care to provide safe drinking water to the communities or people who rely on their supplies.

If you own a drinking water supply that was operating before 15 November 2021 but was not
registered with the Ministry of Health, you have until November 2025 to register with Taumata
Arowai. Full compliance with the Act is not required until November 2028.

Examples of supplies that are often ‘unregistered’ are smaller community water schemes, or
supplies serving marae, papakāinga, rural schools or community halls, or multiple dwellings such as farmhouses that share a bore or water source.

In the meantime, you have a duty of care to make sure the water you provide is safe. If you are
unsure, consider arranging a water quality test. This will give you information about the quality of your water and you can start to plan what you might need to do to make sure your water continues to be safe.

If your house or dwelling has its own domestic drinking water supply, then the WSA doesn’t apply to you. For further information visit the Taumata Arowai website.

The Government is reviewing how to improve the regulation and supply arrangements of drinking water, wastewater and stormwater (three waters) to better support New Zealand’s prosperity, health, safety and environment.  This will result in changes to the definition and responsibilities of private water supplies.  

Information on upcoming national changes to water supply regulation can be found below. 

If you're unsure where your water comes from, you can investigate by visiting QLDC’s Map Navigator. Simply click the ‘Services’ button on the left, then enable the ‘Legend’ key at the top to view the different water supplies. 

A bore extracts water from a source called groundwater, which is water stored deep underground in natural reservoirs called aquifers. More information about groundwater can be found on the ‘Otago Regional Council website. Learn more about groundwater on the Otago Regional Council’s Private bore water supplies page.  

Arsenic is a naturally occurring chemical found in soil and water. It can also be present in food, plants and in some environments from historic mining activities. While low levels are common and generally not harmful, long-term exposure to high concentrations can pose serious health risks. Health New Zealand | Te Whatu Ora has further information about arsenic, and the University of Otago has substantial information on their Arsenic in the environment webpage.  

In regions with schist rock, (like Otago and the Queenstown Lakes District), arsenic can be present in groundwater due to both natural minerals in the ground, and human activities. This is not unique to our area—other parts of New Zealand, including Hawke’s Bay, Waikato, Manawatu, Marlborough, and Canterbury, also face similar issues with arsenic in groundwater. 

Arsenic cannot be removed by normal treatment processes, so even if your water is treated, you need to test regularly to understand how safe it is. It is essential that drinking water is treated with a multi-barrier treatment approach as a key principle of safe drinking water.  

Why test your bore water? 

Because arsenic levels can vary over time and between water sources, it is essential to regularly test private bore water for safety. If you are considering a new water source, it should also be tested for arsenic to ensure it is safe for consumption. If you are not classified as a water supplier with Taumata Arowai – it is still important to test your water. 

Groundwater supplies, like those from private bores, often aren't monitored regularly. This means changes in water quality can happen without anyone noticing. That’s why it's important for people using private water supplies to regularly test their water for arsenic. If you’re considering a new water source, make sure it’s tested to confirm it’s safe to drink. 

Also, remember that weather events like flooding, heavy rain, or power cuts can affect water quality by introducing contaminants. During these times, it’s crucial to boil your water until it can be tested and confirmed safe again. And if you're on the same water supply as others, let them know to do the same. 

Testing seasonally or after events such as those listed above helps to ensure your water is safe to drink. 

How to test your bore water for arsenic 

If your water supply comes from a bore and it hasn’t been tested recently, we strongly recommend getting it tested as soon as possible. If multiple properties share the same water supply, testing can be done collectively for the whole supply. 

If you take water from a private bore water supply, a 2021 Otago Regional Council public meeting gives extensive information about the issue across Otago. 

To arrange testing, contact your water supplier or an accredited laboratory who can undertake the water testing. For peace of mind, we advise hiring a qualified professional to take the water samples, as they can ensure the correct sampling procedures are followed. They can also guide you to an accredited laboratory for the testing. 

• Taumata Arowai, the water regulator, provides a list of accredited laboratories for drinking water testing. Queenstown, Dunedin, and Christchurch all have local labs that can test your water. You can see this list here.  

• To arrange testing, contact the laboratory of your choice for a quote and specific instructions on how to collect the water samples, as well as postage and handling requirements. 

• When ordering the test, be sure to specifically request arsenic testing, as it’s not always included by default. 

Regularly testing your water is the best way to ensure it’s safe to drink.