FAQs on updates to the Drinking Water Quality Assurance Rules 2026

A: Each component of the supply has a different code i.e. Source = S, Treatment = T and Distribution = D, as these are level 3 rules it will be S3, T3, D3. Each module within a component has secondary, and tertiary codes (where rules need to be further broken up, or there are options for which rules can be followed, i.e.

T3.B = Bacterial virus treatment rules

T3.BC = Bacteria virus common rules

T3.BF = Bacteria virus free available chlorine treatment rules

T3.BD = Bacteria virus chlorine dioxide treatment rules

T3.BO = Bacteria virus ozone treatment rules

T3.BU = Bacteria virus UV treatment rules

T3.BU.1 = UV Rule 1

T3.BU.2 = UV rule 2

See Guidance on how the Rules work for more information

A: A downstream supplier is a drinking water supplier that receives drinking water from an upstream supply and then supplies that water to others. To be a downstream supply, the person who owns the downstream drinking water infrastructure must be different from the person who owns the upstream supply.

An upstream supplier is a drinking water supplier that provides drinking water to a downstream supply.

Drinking water is defined by the Water Services Act 2021 (the Act) to mean water used for human consumption, oral hygiene, food or drinking preparation or washing utensils used for these purposes. Drinking water does not include water intended only for irrigation, stock water or other non-human use.

An upstream supplier is responsible for supplying safe drinking water to the point of connection with the downstream supply.

A: Downstream supplies (also known previously as linked supplies) are not defined in the Water Services Act, therefore the Authority conducted some consultation and policy development work in 2025 to further scope out downstream supplies.

• A downstream supplier receives drinking water from an upstream supply and then supplies that water to others
• The supplies are owned by different suppliers
• Additional treatment exists or is needed
• There are additional risk factors, for example extensive storage, medium-high risk of backflow, certain network features such as hydrants.

Downstream supplies have been added to section 6 of the rules as a standalone category. Downstream suppliers will need to follow the General, Treatment, and Distribution rules, as well as any population-based rules that apply, depending on their population size and whether they are a networked supply with treatment, a supply receiving treated water, or a self-supplied building.

A: On-site analysis is carried out at or near the point of sampling using accredited equipment or services, allowing faster results and operational response. Laboratory analysis is undertaken at a fixed facility that samples need to be transported to and may involve more complex or specialised testing, but with longer turnaround times. Under the DWQAR, there is no inherent difference in validity between on-site analysis and laboratory analysis, provided both meet the same quality requirements.

A: Yes, this can be done as a grab sample if the continuous monitoring is in working order and operated and maintained according to manufacturer specifications.

A: Yes, Rule G.CM.3 has been updated to state compliance periods.

A: Please refer to G.CM.3, G.CM.4 and G.CM.5 for exact requirements. 

A: We don’t specify set timeframes – these are set by the manufacturers of the monitoring equipment due to the varied quality of the instruments, pace of measurement, drift, age of components and other factors may influence instrument accuracy.

A: We are working through this and further guidance will be available soon.

A: Reported via the approved forms into Hinekōrako using:

• Webform via Hinekōrako for level 1 and level 2 supplies only
• API (typically third-party software)
• Excel (new templates will be made available soon)

A: Some rules are designated as non-reporting rules and water suppliers are not required to report on their performance against those rules, though they are still expected to comply with non-reporting rules.

A: The reporting rules set out what needs to be reported to the Authority each year, but suppliers no longer need to report whether they met these rules specifically. These changes are intended to reduce administrative burden of reporting information the Authority won’t use.

A: We have amended the rule to allow for multiple UV units to be used as part of the full UV rules suite. Treatment of the water is considering a whole process – not individual UV reactors. Suppliers can calculate their percent compliance on the combined data for all UV reactors operating with the compliance period.

A: Depending on which part of the rules this applies to, it could be a hydrogeologist, drinking-water scientist/engineer, or a broader category of water-sector professionals with proven competency. The Authority will develop further guidance on who may be considered a SQEP.

A: The supplier should determine if a person meets the SQEP requirements of the relevant rule. The supplier should keep a record of the advice given by a SQEP and their qualifications and experience. There is no approval/verification process from the Authority, but we may ask for details on how a supplier determined whether a person is suitably qualified and experienced. 

A: A SQEP can be internal staff or an external consultant. They do not need to be independent of the supplier.

A: If someone is not a SQEP, the assessment will not be valid.

A: To simplify the rules and reduce the number of footnotes and cross referencing, requirements in footnotes have generally been written into the rules explicitly, or removed and considered for future inclusion in guidance. 

A: Source water class will depend on the type of source water you have, and what infrastructure you have in place to abstract the water i.e. sanitary bore head. 

A: You would need to start as an Interim Class A, Interim Class B or Class C classification until enough testing has been completed to show that the criteria are met.

A: See table below:

A: If you are moving up a Class i.e. moving from Class C to Class B, then an assessment prior to this change is required.

A: The proposed Class A is for groundwater abstracted from a depth of greater than 30 metres that is highly unlikely to be contaminated with bacteria, viruses or protozoa. Suppliers will not be required to have primary treatment barriers in place for these contaminants. 

This will allow suppliers to avoid the cost of installing UV disinfection or chlorine contact time infrastructure that is required where chlorine is used to control bacteria and viruses. Chlorine is still required to be added to these supplies to ensure that water distributed in a network contains residual chlorine.

A: F‑specific bacteriophages are coliphages/viruses that infect certain types of bacteria and can be used as indicator of viral contamination risk in drinking water and source waters.

A: During consultation on the updated rules, there was not much support for letting suppliers choose the viral indicator, so a more specific approach was used instead 

A: Self-supplied buildings, Water Carriers and Community Drinking Water stations are not able to use this Class type due to their being specific rules for these supply types. 

A: No, only bores that are moving to a higher classification (i.e. going from Class B/1 to Class A for example). If you are staying at the equivalent classification in the new system, then no reassessment will be needed until the 5-year mark.

A: You would revert to Class C. Further guidance will be provided. In both cases the supply would still need to have a sanitary bore head, have continuous monitoring for some determinands and have residual chlorination. These additional requirements of Interim classes can reduce the risk to consumers (including in the interim period). They are also good practice to have in place even if your source water does not meet the monitoring requirements to be classified as Class A or Class B.

A: Yes, this has been included based on feedback from consultation.

A: If you are following the level 3 source water rules, only new Class D sources do not require an assessment. All other new sources would require an assessment.

(i.e. Current Class 1 that does appropriate viral testing between July 2026-June 2027 to meet the requirements for Class A required could start at Class A on transition date.) 

A: Yes. These source classes should already have 3 years of Total coliforms/E. coli testing so would only need to supplement this with Viral testing in this example.

A: This is based on scientific review of literature and data in New Zealand from our Technical Panel experts.

A: Suppliers’ capability and understanding of cyanobacteria and cyanotoxin risk varies significantly. Many suppliers have undertaken significant source water testing and analysis and have a good idea of their toxin risk. The Rules allow suppliers to either start with indicators (e.g. microscopy or visual monitoring) in their source water and progress to toxin testing where results indicate a potential risk, or test directly for cyanotoxins in treated water if this approach is preferred.

A: It's a useful indicator relating to water treatment. It is not required for Class A and B, and we have removed the requirement to sample for colour in Class C groundwater, based on feedback from consultation.

A: Fluoride can occur naturally in source waters, and elevated levels of fluoride can be present in some groundwater in geologically volcanic areas. Fluoride may not be removed by filtration or other typical treatment processes used in New Zealand. Fluoride in source water will likely be present in drinking water from these sources. A drinking water supplier needs to understand whether chemicals in source water will or will not likely be removed by their treatment plants and take appropriate steps to monitor those chemicals in drinking water and take action to protect public health. If the MAV is exceeded in drinking water, this is considered a non-compliance with the Drinking Water Standards.

A: Self-supplied buildings do not require chlorine residual so do not need to follow BC.3 and BC.4. This is explicitly stated in these rules.

A: The standards that applied have been added to the interpretation section, it means one of the following: 

• NSF/ANSI 55 Class A (for populations of up to 5000)
• USEPA Ultraviolet Disinfection Guidance Manual
• DVGW Technical Standard W294-1:2023-12
• ÖNORM M 5873-1: 2020 01 01
• DIN 19294-1:2020-08
• ÖNORM M5873 (if installed before 1 January 2020) 

A: They would need to comply with the common rules (BC.3 and BC.4) as residual disinfection is still required. 

A: When the treatment plant is making water that is being supplied to consumers prior to it entering the distribution zone, it is producing drinking water. Water that is diverted to waste streams (and therefore not supplied to consumers) is not required to be compliant. Many plants across New Zealand have run-to-waste as a means to mitigate the risk of drinking water being non-compliant. The Authority expects all drinking water supplied to consumers is compliant.

A: Chlorine dioxide was originally proposed for removal as a bacteria and virus treatment option, but that proposal was reversed after consultation. There was sufficient opposition to removal, so it was reinstated and rules updated based on external technical advice. 

A: Some feedback in consultation was received. After discussion with industry experts, it was confirmed that timing can be increased. Noting that storage of the sensors away from light is important to maintain validity.

A: To simplify the rules and reduce the number of treatment options suppliers needed to select from. Suppliers can still use those removed options as part of their treatment process but not for log credits for protozoa removal.  

A: Suppliers can implement any treatment process to manage risk within their supply for additional security and/or turbidity control; however, this wouldn’t count towards additional log credits. The treatment rules provide the minimum requirements suppliers must meet to be compliant.

A: Where water from run/filter-to-waste or waste from treatment processes is effectively separated from solids to a level where the water can be recycled. The recycled water should have a sufficiently low turbidity that will not affect the safety or effectiveness of treatment processes if added to the start of the treatment processes with other source water. 

A: Yes, depending on the type of recycled water, see T3.PC.5 (b) – total recovered water in a raw water storage is <20% of the stored raw water volume and (c) it is subject to flow equalisation demonstrated by continuous monitoring so that either the instantaneous total recycled water return rate does not exceed 10% of the plant inflow; or a metric is developed by a SQEP to ensure the volumetric ratio of recycle water to raw water and/or plant inflow does not exceed 10% for more than 95% of each day or 15% for more than 15 consecutive minutes.

A: All treatment chemicals that are used within the supply – excluding sodium hypochlorite and chlorine dioxide that is generated on-site. 

A: Suppliers should work with their chemical providers to ensure the chemicals they use are fit for purpose in drinking water applications and review the certification provided with their chemicals as well as follow all instructions for storing and using the chemicals. 

A: The schedule should include all the chemicals that are used within the treatment plant and chemicals that may be formed in the treatment process. 

A: It is used to ensure a water supplier can demonstrate that the appropriate chemicals are being monitored and will not create a health risk. 

A: The rule should improve the quality of chemicals being sold to drinking water suppliers. Contamination of chemicals used in drinking water can and has occurred in New Zealand and abroad. This compliance requirement puts in place one assurance mechanism to keep consumers safe and will help prevent contamination of drinking water.

A: As of the publication of this web content, the Authority has not specified any standard relating to chemical supply, however, we may use this option in the future if the need arises to ensure the safety of drinking water. 

A: You are exempt from T3.CH.1 as the chemical is created on site by the supplier so there will not be any certificates provided. However, these processes form chemicals used in the treatment process and this, including byproducts from these processes, must be monitored for as per T3.CH.2 and T3.CH.3.

A: The risk the new chemical rules are addressing is poor chemical quality which may have an impact on consumers’ health.

A: No, the onus is on the water supplier to get certificate of quality from the chemical supplier and ensure these chemicals are safe for use in their drinking water supply. The Authority does not regulate chemical suppliers.

A: No - testing needs to be completed by an accredited laboratory.

A: Yes - we have provided multiple pathways for testing source or treated water for cyanobacterial presence of cyanotoxins or cyanotoxin producing genes. 

A: Yes, we have done some analysis on this and the capability of labs across NZ and provided multiple pathways to help ensure appropriate laboratory coverage and capability.