OIA Ref: CAS-01826-K7Q8Q5
28 February 2024
J Wilson
[FYI request #25270 email]
Tēnā koe J Wilson
Request for information relating to the chemical composition of New Zealand water
Thank you for your email dated 21 December 2023, requesting the following information, which we
have considered under the Official Information Act 1982 (OIA):
“what chemicals can be found in New Zealand water -- in reservoirs, lakes, streams, rivers, the sea,
drinking and washing water. Please detail the chemicals and metals, and their levels, found in New
Zealand water over the last five years.
Are there metals in the water of any type or location, such as copper, mercury, lead, cadmium,
aluminium, barium, iron, strontium, graphene? What are the levels of these or other metals in the
water? Are they all removed from drinking water?
Are there any micro-plastics or nanoparticles found in the water of any type, and if so, what are they,
and what are they levels of them? If so, where do these items come from?.”
The scope of your request is quite broad. We attempted to clarify the scope with you on 11 and 29
January 2024, but have not had any response from you.
We have interpreted your request as follows:
• Where can I find more detail on chemical testing of different types of water in New Zealand,
e.g. who is responsible for what?
• What chemicals (of any type) are required to be tested for in sources of drinking water and
treated drinking water?
• What records do you have on chemicals (of any type) found in sources of human drinking water
and treated drinking water including the last five years of historical records?
• Are microplastics or nanoparticles tested for in sources of drinking water and treated drinking
water, and at what levels are they found?
Our response to your request is set out below.
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Response
Background
1. Taumata Arowai–the Water Services Regulator is a Crown entity established on 1 March 2021 by
the Taumata Arowai–the Water Services Regulator Act 2020. Our functions include monitoring
and enforcing compliance with relevant drinking water legislation and standards, and other
regulatory requirements for which we are responsible.
2. Taumata Arowai became the water services regulator on 15 November 2021 when the
responsibility for regulating drinking water transferred from Manatū Hauora | Ministry of Health
to us with the commencement of the Water Services Act 2021 (the Act).
3. The Water Services (Drinking Water Standards for New Zealand) Regulations 2022 (the
Standards) and the Drinking Water Quality Assurance Rules (the Rules) came into force on 14
November 2022, and replaced the Drinking-water Standards for New Zealand 2005 (Revised
2018) (the 2005 Standards).
4. The Standards established revised Maximum Acceptable Values (MAVs) for chemicals in drinking
water. The Rules set minimum requirements for treating and monitoring drinking water, which
drinking water suppliers must follow based on the supply type and the population they serve.
Responsibilities of drinking water regulation
5. Taumata Arowai is responsible for regulating drinking water suppliers.
6. Drinking water suppliers are responsible for monitoring their drinking water supplies, and
responding when monitoring shows that a chemical has exceeded a MAV.
7. The Ministry for the Environment and regional councils are responsible for environmental
regulation, including the protection of bodies of water.
8. If a supplier’s drinking water does not comply with the Standards, such as a MAV being
exceeded, the supplier must:
(a) take immediate action to ensure that public health is protected; the action that would be
taken would be proportionate to the chemical and the level of the chemical detected in
drinking water;
(b) notify Taumata Arowai of the non-compliance; this allows us to be aware of all MAV
exceedances in registered drinking water supplies and follow up if necessary;
(c) investigate the source or cause of the non-compliance;
(d) take remedial action to rectify the situation;
(e) identify and implement measures required to ensure that the event does not reoccur; and
(f) take all practicable steps, to the satisfaction of Taumata Arowai, to advise affected
consumers and drinking water suppliers that drinking water does not comply with the
drinking water standards and what measures should be taken to protect public health (for
example, issuing a consumer advisory).
Chemicals required to be tested for in drinking water
9. The Rules were published in July 2022 and require drinking water suppliers to sample their
source water and drinking water for chemicals from 14 November 2022. These are the minimum
requirements for testing that suppliers must undertake, but the supplier must also undertake
additional monitoring if the supplier identifies that a chemical may pose a risk to their supply.
10. Below is a summary table of the Rules which require chemicals to be tested for by water type,
the rule number, and the supply population.
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Water type
Rule
Required Monitoring*
Supply population
range
Source Water:
S1.1 and  Arsenic, Boron, Iron, Manganese,
26-500 people
Groundwater and  S2.1
Nitrate
Surface Water
Source Water:
S1.2 and  Benzo[a]pyrene, Cadmium, Copper,
26-500 people
Roofwater
S2.2
Lead, Zinc
Source Water: If
S2.6
Cyanobacteria and Cyanotoxins
>101 people
cyanobacteria risk
is medium or high
Source Water of
S3.3 and  Alkalinity, antimony, arsenic, barium,
>500 people
Large Supplies
S3.6
cadmium, calcium, chloride, chromium,
copper, iron, lead, magnesium,
manganese, mercury, nickel, nitrate,
sodium, sulphate
Also, any additional chemicals which
have been identified in the supply’s
Source Water Risk Management Plan as
presenting a potential risk to the
drinking water supply
Source Water:
S3.4
Radioactivity, potassium
>500 people
Additional
Groundwater
monitoring
Drinking Water:
T2.1,
Chlorate
>101 people
Monitoring at the  T3.92,
Chlorine
treatment plant
T3.93,
Fluoride (only if added to the supply).
T3.96
Also any other chemicals which may be
added or formed during the treatment
process.
Drinking Water:
D2.1,
Chlorine, antimony, cadmium,
Monitoring in the  D3.18,
chromium, copper, lead, mercury,
>100 people
distribution
D3.19,
nickel, zinc
network
D3.20,
D3.22
*Health related chemicals with MAVs are underlined. Other chemicals not underlined can influence
aesthetics of the water.
11. The results of the chemical testing from the Rules in the table above are also required to be
reported to Taumata Arowai annually. These suppliers must provide their first annual
compliance report on the Rules this year. Once Taumata Arowai receives the required data sets
from suppliers across the country, we will assess the data.
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Compliance data yet to be col ected
12. Taumata Arowai currently holds a growing set of raw data from suppliers which have reported
ahead of the annual deadline. We expect this data set to continue growing into a very large,
complex data set in the coming weeks. This complex data set wil require substantial collation in
order to provide this data for your request.
13. We intend to present data related to the Rules publicly as we continue to integrate new data
into our systems. Some information will be available in our Drinking Water Regulation Report for
2023, which is due to be published by 1 July 2024. We are also required to report source water
quality monitoring to regional councils annually. We expect to do this within a year of receiving
the data.
14. Therefore, the Rules data set identified for this part of your request is refused under section
18(f) of the OIA, on the basis that the information requested cannot be made available without
substantial collation or research.
15. We do not consider that the need to withhold for these reasons is outweighed by other
considerations which make it desirable, in the public interest, to make the information
available.
16. You are welcome to contact Taumata Arowai to clarify the scope of your original request via
[Taumata Arowai request email]. This clarification will be treated as a new request.
17. Suppliers are the owners of this data and are required to hold these records by the Act.
Suppliers also have a responsibility to communicate with their consumers about the quality of
their drinking water.
18. If you are interested in a specific registered drinking water supply, you may consider contacting
the owner or operator of that supply.
19. Our Public Register of Drinking Water Supplies includes some information that registered
drinking water suppliers provide to us about their supplies. You can search and find the drinking
water suppliers for each geographical area in the register located on our website: Public Register
of Drinking Water Supplies.
Records held on chemicals found in drinking water
20. Since 15 November 2021 we have been recording when laboratories and suppliers notify us of
chemical test results which exceed a MAV.
21. We also hold water quality data that was submitted by suppliers voluntarily to the Ministry of
Health prior to 15 November 2021.
22. We are able to provide you with the following records of chemicals in drinking water:
a) Notifications of water supplies exceeding the MAV of a chemical in the Standards since 15
November 2021 when Taumata Arowai took over regulation of drinking water from the
Ministry of Health. These results are attached to this response as Appendix One.
b) Historical data prior to 15 November 2021 provided to us by the Ministry of Health on water
suppliers exceeding the MAV for a chemical. This data is attached to this response as
Appendix Two.
23. In regard to Appendix Two, Taumata Arowai cannot provide any quality assurance on this data.
Withholding address information
24. Where indicated, some street addresses have been withheld from Appendix Two as it is
necessary to protect the privacy of natural persons, including that of deceased natural persons
under section 9(2)(a) of the OIA.
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25. We do not consider that the need to withhold for these reasons is outweighed by other
considerations which make it desirable, in the public interest, to make the information
available.
Microplastics and nanoparticles
26. Taumata Arowai does not hold data on microplastics or nanoparticles found in New Zealand
drinking water.
27. As noted in our email to you on 29 January 2024, we have transferred this part of your request
under section 14 of the OIA to the Ministry for the Environment, as they are the best agency to
respond.
Finding specific information on your water supply
28. We recommend contacting your local council if you are after information on your specific water
supply. You can check who your drinking water supplier is on the Public Register. If you have
concerns about your drinking water supplier, we recommend you firstly contact your supplier.
More information is available here: Are you concerned about your drinking water? | Taumata
Arowai.
Right to complain
You have the right by way of complaint to the Ombudsman under section 28(3) of the OIA to seek an
investigation and review of this response. Information about how to make a complaint is available at
www.ombudsman.parliament.nz or freephone 0800 802 602.
Ngā mihi
Steve Taylor
Head of Regulatory
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Document Outline