Drinking Water Quality Assurance Rules
The Water Services Authority – Taumata Arowai is responsible for establishing Drinking Water Quality Assurance Rules.
Drinking Water Quality Assutance Rules
The Drinking Water Quality Assurance Rules (the Rules) set out the minimum requirements for treatment, monitoring and reporting that drinking water suppliers must meet.
All registered drinking water suppliers must comply with the Rules or, if they qualify, follow an Acceptable Solution (unless they have an exemption).
Current Drinking Water Quality Assurance Rules
Current Drinking Water Quality Assurance Rules (issued in 2022 and revised in 2024)
Different rules apply depending on the size and nature of the supply, which range from very small community suppliers serving fewer than 25 consumers to large network suppliers (typically councils) serving urban areas.
Monitoring and reporting requirements
Monitoring requirements
The Rules set out the monitoring and laboratory analysis of water samples that must take place regularly at the source of a drinking water supply, following treatment and across the distribution system, depending on the size and nature of the supply.
Monitoring checks that quantities of metals, chemicals and microorganisms in a drinking water supply sit within Maximum Allowable Values (MAVs) as set out in the Drinking Water Standards.
Reporting requirements
Most registered drinking water suppliers must also report to us regularly, confirming that they are meeting their obligations under the Rules.
Suppliers may need to undertake additional treatment or monitoring if they identify specific risks or hazards within their supplies.
Upcoming changes to the Rules
In June 2026 the Authority published updated Rules, following consultation. Most of the changes relate to level 3 supplies (supplying over 500 people) and aim to make the Rules clearer and easier to use.
There are also a small number of Rule changes for all levels (1,2 and 3) including changing reporting from a calendar year to a financial year.
The new Rules will come into effect on 1 July 2027. Until then, the current Drinking Water Quality Assurance Rules 2022 (Revised 2024) remain in effect.
View the updated Rules – Water Services (Drinking Water Quality Assurance) Rules 2026
Previous updates to the Rules
In 2024 the Rules were revised for supplies that serve 500 or fewer people. The revised rules (which came into effect on 1 January 2025) clarified monitoring and reporting requirements for very small communities, small and medium supplies operating under level 1 and level 2 rules.
See guidance on the revised Rules (2024) for very small supplies
See guidance on the revised Rules (2024) for small supplies
See guidance on the revised Rules (2024) for medium supplies
If you need to view earlier versions of the Rules, they are available on our legislation and regulations page.
Standards and Aesthetic Values
Collectively, the Rules, Standards and Aesthetic Values set minimum requirements for drinking water suppliers and help ensure communities receive safe drinking water.
Drinking Water Standards
Drinking Water Standards set the Maximum Acceptable Values (MAVs) for a range of substances which can affect the safety and quality of drinking water. The MAVs are based on guideline values set by the World Health Organisation (WHO).
View the Drinking Water Standardsoutbound
Aesthetic Values for Drinking Water
Drinking water not only needs to be safe, but it also needs to look, taste and smell acceptable too. The Aesthetic Values for Drinking Water specify or provide minimum or maximum values for substances and other characteristics that relate to the acceptability of drinking water.
Alternatives to the Rules
Acceptable Solutions
Some smaller or rural drinking water suppliers might be able to use an Acceptable Solution to meet their legal obligations. If they follow an Acceptable Solution in full, they do not have to follow the Rules.
Learn more about Acceptable Solutions
Exemptions
For a small number of suppliers, it may be disproportionate to require compliance with some legislative requirements and duties due to the scale, complexity and risk profile of their water supply. In such cases, we may be able to exempt suppliers from certain requirements of the Act if they are still able to ensure safe drinking water is provided to consumers.