Private drinking water supplies

Owners of private drinking water supplies are responsible for maintaining, monitoring, and treating their own supply.

Your responsibilities as a private supplier

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.

Upcoming national changes

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. 

Arsenic and other chemicals in groundwater

Arsenic is a naturally occurring chemical element, present at low levels in all soil, water, plants, animals and foods. The main way people are exposed to arsenic is through the small amounts of this element that are naturally present in food and drinking water. High and chronic exposure to arsenic can be harmful to human health.

Arsenic in groundwater can originate from human and natural sources.  Elevated arsenic levels can occur naturally in groundwater due to the presence of specific materials in the geology of the aquifer. However, the release of arsenic from those materials can happen in a specific area without happening throughout the rest of the aquifer system. The level of arsenic may also be different in each ground or surface water source and may change over time.    It is therefore important to regularly test your water. 

Naturally occurring arsenic has been detected in areas of Otago, including the Queenstown Lakes District.   This is not unique to Otago and  has been reported from other areas of New Zealand (e.g. Hawke’s Bay, Waikato, Manawatu, Marlborough, Canterbury) and internationally.   This reinforces the need to regularly monitor your supply.  

When a new water source is being considered,  the water must be tested to ensure that the water is potable before resources are invested in developing the supply for drinking and sanitation purposes. 

Routine testing 

Groundwater bore sources used for drinking water and sanitation purposes should be routinely tested for metals such as arsenic and lead, as well as other parameters, in order to ensure that the requirements of the Drinking Water Standards for New Zealand 2005 (revised 2018) are met.

Further information is available on the ORC website, including a list of suggested sample parameters and information on how to improve your bore security.