FAQs on updates to the Drinking Water Quality Assurance Rules 2026
These FAQs are intended to support drinking water suppliers to understand and apply the proposed Drinking Water Quality Assurance Rules (the Rules). It provides responses to common questions about how the rules work, how they apply in practice, and where further guidance may be needed.
Use this document as a practical reference alongside the Rules and any supporting guidance. Where an answer is marked as still in development, further information will be provided as policy positions and guidance are finalised.
FAQs for all levels
How the rules work
Q: What do the letters and numbers in each rule represent?
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
Continuous monitoring and sampling
Q: What is on-site analysis and how does this differ to laboratory analysis?
A: On-site analysis is carried out at or near the point of sampling using accredited equipment or services, allowing for 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 Rules, there is no inherent difference in validity between onsite analysis and laboratory analysis, provided both meet the same quality requirements.
Q: Can I use data from my continuous monitoring equipment instead of monitoring using analysis of grab samples?
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.
Q: If a grab sample result fails to meet the monitoring limit - should the supply be considered non-compliant for the relevant rule for the day or the compliance period?
A: Yes, Rule G.CM.3 has been updated to state compliance periods.
Q: What happens if our continuous monitoring data cannot be recorded?
A: Please refer to G.CM.3, G.CM.4 and G.CM.5 for exact requirements.
Q: What is the minimum frequency for calibration and verification of common compliance monitoring instruments?
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.
Q. Does the term "chemical determinands" include onsite field tests for Free Available Chlorine (FAC)? Will the supplier carrying out FAC testing for compliance need to be accredited by IANZ?
A. Free Available Chlorine (FAC) is not intended to be covered by G.SM.3 but instead is expected to be covered by G.SM.4. We acknowledge that the rule as it is written does not make this clear and are considering whether greater clarity can be provided. The same applies for on-site testing for pH and turbidity.
Q: Does accreditation apply to routine hand-held field measurements?
A: G.SM.3 is intended to ensure IANZ-accredited laboratories and on-site analysis systems are used for microbiological and chemical determinands, particularly those with MAVs. The rule is not intended to apply to analysis for FAC which is generally undertaken by continuous monitoring or handheld analysers. We acknowledge that the rule as it is written does not make this clear and are considering whether greater clarity can be provided. G.SM.4 acknowledges that some determinands, particularly turbidity, colour and some other determinands, are regularly monitored by suppliers. Hand-held instruments and continuous monitoring instruments can be used for compliance purposes if they are maintained and operated in accordance with manufacturer instructions. These instruments must be fit for purpose for the application, including detection limit, range and sensitivity sufficient to detect non-compliance with the limits in the Rules. When these instruments are used for compliance, there is no requirement for IANZ accreditation.
Reporting requirements
Q: How will reporting work during the transition to the new reporting year, including any interim six-month reporting period?
We have extended the reporting deadlines in recognition of the additional work required of suppliers. These transitional arrangements will support suppliers through the change while continuing to provide assurance of key compliance requirements. We have prepared a table to summarise the transitional arrangements for Rules reporting over the next year.
Q: How should non-compliance information be reported to the Authority, and what approved forms can be used?
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)
Q: What does a non-reporting rule mean?
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.
Q: Why are “reporting rules” listed as a rule type of “non-reporting”?
A: The reporting rules set out instructions about the information water suppliers need to provide to us and how they should do that when reporting performance against monitoring and assurance rules. Because these rules are really just instructions on how to do things, we don’t require water suppliers to report (or tell us about) their performance against them. For this reason, they are categorized as non-reporting rules.
Q: How should compliance be calculated and reported when there are multiple UV reactors running in parallel?
A: We have amended the rule to allow for multiple UV units to be used as part of the full UV rules suite. The Rules apply to UV treatment of the water, not the performance of an individual UV reactor where more than one is being used. Suppliers can calculate their percent compliance on the combined data for all UV reactors operating within the compliance period.
FAQs for level 3
Suitably qualified and experienced persons
Q: What is meant by a suitably qualified and experienced person (SQEP) under the rules?
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 suitably qualified and experienced person (SQEP).
Q: How should a supplier determine whether a person is a SQEP, and what evidence should be kept?
A: The supplier should determine if a person meets the suitably qualified and experienced person (SQEP) requirements of the relevant rule. The supplier should keep a record of the advice given by a SQEP and their qualifications and experience. The Authority provides no approval/verification process around this but we may ask for details on how a supplier determined whether a person is suitably qualified and experienced.
Q: Does a SQEP need to be external or independent, or can they be internal staff?
A: A suitably qualified and experienced person (SQEP) can be internal staff or an external consultant. They do not need to be independent of the supplier.
Q: What happens if an assessment is completed by someone who is not a SQEP?
A: If someone is not a suitably qualified and experienced person (SQEP), the assessment will not be valid.
Q: How does the work Water NZ is doing regarding an authorisations framework relate to suitably qualified and experienced person requirements?
A: The Authority and the Ministry of Cities, Environment, Regions and Transport (MCERT) are working together to develop an authorisations framework. An authorisations framework may include requirements about what skills, qualifications or experience people need to have to work on a drinking water supply or wastewater network. We are considering whether suitably qualified and experienced persons (SQEPs) under the Rules also need to be authorised. We expect to carry out public consultation on a proposed authorisations framework in the first half of 2027. In the meantime, the Authority plans to release guidance for each situation where a SQEP is required.
Removing footnotes
Q: What is the reason for the removal of footnotes?
A: To simplify the Rules and reduce the number of footnotes and cross referencing, requirements in footnotes have generally been written explicitly into the Rules or removed. We may consider removed footnotes for future inclusion in guidance.
S3 Source classification
Q: How do I classify my source class?
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.
See the updated source water classes for large drinking water suppliers
Q: What do I do if I have a new source that I want to follow Class A or B but don’t have the testing results to confirm that it meets the criteria?
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.
Q: If I am in Class 1/2/3/4 now, what will I be in the new Rules as a default?
A: See table below:
| Current Classes | Default New Classes |
| N/A | Class A |
| Class 1 | Class B |
| Class 2 | Class C |
| Class 3 | Class D |
| Class 4 | Class C |
Q: What do I do if I want to change my class to a different class?
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.
Q: Why is there a new Class A?
A: 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. Ongoing monitoring for bacterial and viral indicators is required for Class A groundwater under Rules S3.AB.2 and S3.AB.3.
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 combat bacteria and viruses. Chlorine is still required to be added to these supplies to ensure that water distributed in a network contains residual chlorine.
Q: What is F-specific bacteriophage?
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.
Q: Why does Class A require testing for F-specific bacteriophage specifically and not other viral indicators?
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
Q: Why does Class A/Interim Class A only apply to networked supplies?
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.
Q: Will all suppliers need to undertake full SQEP-led source water assessments and bore classifications?
A: No, only bores that are moving to a higher classification, e.g. going from Class B/1 to Class A. If you are staying at the equivalent classification in the new system, then no reassessment by a suitably qualified and experienced person (SQEP) will be needed until the five-year mark.
Q: : When adopting an Interim Class - What happens after two years, if the Source does not meet the criteria? Have we put consumers at risk during the interim period?
A: No, only bores that are moving to a higher classification, e.g. going from Class B/1 to Class A. If you are staying at the equivalent classification in the new system, then no reassessment by a suitably qualified and experienced person (SQEP) will be needed until the five-year mark.
Q: If I have a Class C bore, can I still use representative sampling?
A: Yes, this has been included based on feedback from consultation.
Q: Do I need to do an assessment on a new source?
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.
Q: If supplier completed appropriate testing/assessment by July 2027 – can a supplier can start at a higher-Class level?
For example, if a current Class 1 does appropriate viral testing between now and June 2027 to meet the requirements for Class A, could it start at Class A on transition date?
A: Yes. In this example, this source class should already have completed three years of total coliforms/E. coli testing so would only need to supplement this with viral testing.
S3/T3 Cyanobacteria/cyanotoxin monitoring
Q: What is the rationale for specifying 20% benthic mat coverage as the threshold for cyanobacteria monitoring?
A: This is based on a scientific review of literature and data in New Zealand from our technical panel experts.
Q: Why are there so many options for cyanobacteria/cyanotoxin monitoring in the rules?
A: Suppliers’ capability and understanding of cyanobacteria and cyanotoxin risk vary 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. Alternatively, they can test directly for cyanotoxins in treated water if this approach is preferred.
Q: Are there reliable test kits that would enable water suppliers to carry out their own testing?
A: No. Testing needs to be completed by an accredited laboratory.
Q: Can toxigenic gene testing be used as an early warning screening tool to assess cyanotoxin producing potential before undertaking cyanotoxin testing?
A: Yes. We have provided multiple pathways for testing source or treated water for cyanobacterial presence of cyanotoxins or cyanotoxin-producing genes.
Q: Are there sufficient levels of services around New Zealand able to support water suppliers in meeting the new requirements under the cyanobacteria and cyanotoxin monitoring rules?
A: Yes. We have looked into this and are satisfied that there is appropriate laboratory coverage and capability across the country.
Q: Can the report backing the cyanobacteria cell-count methodology be shared?
A: If you would like to see the report, please request it by emailing technical@taumataarowai.govt.nz
Q: Can existing cyanobacteria management plans still be relied on?
A: Existing plans may be retained and included in the source water risk management plan and drinking water safety plan documentation and procedures. Regardless of what is included in a supply cyanobacteria management plan, the requirements set out in the Rules relating to cyanobacteria and cyanotoxins must be complied with.
S3 Other source rules
Q: Why are you requiring monitoring for colour in source water?
A: Monitoring for colour is only required in rule S3.CD.3 source water rules. Colour is 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.
Q: Monthly fluoride monitoring in source water is a new requirement. What constitutes non-compliance?
A: Fluoride can occur naturally in source water, 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 are likely (or not) to be removed by its treatment plant/s. Suppliers should 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 non-compliance with the Drinking Water Standards.
T3 Bacteria/Virus Rules
Q: I have a self-supplied building supply with a base population over 500 people, do I need I need to meet T3.BC.3 and T3.BC.4?
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.
Q: What are the designated UV validation standards considered appropriate for UV 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)
Q: If a supplier elects to use ozone or UV for compliance under T3.BC.2, would the supplier still need to comply with rules BC.3, BC.4, BF.1 and BF.2?
A: They would need to comply with the common rules (BC.3 and BC.4) as residual disinfection is still required.
Q: For rule T3.BC.4, what does “the plant is producing drinking water” mean?
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 way to mitigate the risk of drinking water being non-compliant. The Authority expects that all drinking water supplied to consumers is compliant.
Q: The Authority proposed removing the chlorine dioxide option for Bacteria/Virus treatment, why has it been kept?
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.
Q: Why has the UVI sensor timeframe been increased to 24 months?
A: Following feedback in consultation and discussion with industry experts, we have confirmed that timing can be increased. Please note that storage of the sensors away from light is important to maintain validity.
T3 Protozoa Treatment Options
Q: Why have we removed treatment options (for example second stage filtration)?
A: We have done this to simplify the Rules and to reduce the treatment options suppliers need to select from. Suppliers can still use those removed options as part of their treatment process but not for log credits for protozoa removal.
Q: Can a supplier elect to have more treatment than the rule require?
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.
Q: Can the treatment processes relating to protozoa (which have been removed from the Rules) still be used by suppliers?
A: The updated Rules come into effect from 1 July 2027. Up until then, suppliers can continue to use treatment processes relating to protozoa to gain log credits for removal of protozoa. If a water supplier would like us to reconsider this, we request they contact us to discuss further.
T3 Treatment Recycling Rules
Q: What does ‘effective solids/liquid separation’ mean?
A: It means 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.
Q: Can you recycle more than 10% of water?
A: Yes, depending on the type of recycled water. Rule T3.PC.5 (b) allows total recovered water in a raw water storage to be less than 20% of the stored raw water volume. T3.PC.5 (c) requires flow equalisation demonstrated by continuous monitoring. Either the instantaneous total recycled water return rate must not exceed 10% of the plant inflow; or a suitably qualified and experienced person (SQEP) must develop a system (described in the rule as one or more metrics) to ensure the volumetric ratio of recycled 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.
T3 Chemical Rules
Q: What chemicals should we be testing for? (see Rule T3.CH.1)
A: You need to test for all treatment chemicals that are used within the supply excluding sodium hypochlorite and chlorine dioxide that is generated on-site. Monitoring related to sodium hypochlorite and chlorine dioxide generated on-site is still required under T3.CH.2 and T3.CH.3.
Q: How do water suppliers demonstrate chemicals are “safe”? (See Rule T3.CH.1)
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.
Q: How do I prepare a schedule of chemicals? (See Rule T3.CH.2)
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.
Q: How will this chemical schedule be used? Is it solely a risk management exercise for the water supplier?
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.
Q: Why is this information now required?
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.
Q: What is a specified Standard?
A: To date, 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.
Q: If we generate sodium hypochlorite or chlorine dioxide on site, why do we not need a certificate of analysis/conformance?
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 as per T3.CH.2 and T3.CH.3.
Q: What is the risk these new chemical rules are trying to address?
A: The risk the new chemical rules are addressing is poor chemical quality which may have an impact on consumers’ health.
Q: Can the Rules require chemical suppliers to have some obligations around chemical safety?
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.
T3 Cyanotoxin Monitoring Rules
Q: Are there reliable test kits that would enable water suppliers to carry out their own testing?
A: No - testing needs to be completed by an accredited laboratory.
Q: Can toxigenic gene testing be used as an early warning screening tool to assess CB toxin producing potential before undertaking cyanotoxin testing?
A: Yes - we have provided multiple pathways for testing source or treated water for cyanobacterial presence of cyanotoxins or cyanotoxin producing genes.
Q: Are water suppliers going to be able to get contracts with a level of service capable of meeting new monitoring requirements with cyanobacteria and cyanotoxin monitoring rules?
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.
D3 Distribution Monitoring Rules
Q: Why have the proposed pressure rules been removed?
A: The approach to pressure varies across the country. The Authority has begun work to look at sector-wide risks in relation to distribution management in New Zealand to ensure any risks are being managed by suppliers. Our work may include developing fit-for-purpose rules and guidance relating to pressure maintenance and management of networks to reduce the likelihood of recontamination of drinking water as it transits underground networks.
Q: Are monthly requirements interpreted as each calendar month?
A: Yes.
Downstream supplies
Why have downstream supplies been added to these rules
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.