Drinking-water legislation

The Health Act 1956 was amended by the Health (Drinking-Water) Amendment Act in October 2007 and aims to protect public health by improving the quality of drinking-water provided to communities.

More information on the legislation is provided on this page:


The Act provides a flexible, risk management based and outcome focused legislative framework for networked drinking-water supplies.

The main duties in the Act apply to supplies that serve:

  • 25 or more people for 60 or more days per year; or
  • if there are fewer than 25 people, but 6000 or more ‘person/days’ (that is the number of people multiplied by the number of days they receive water from the supply).

These main duties include obligations to:

Supplies that serve fewer people need to be included on the Register of Drinking-water Supplies, which is free and involves no other obligations.

The Act commenced on 1 July 2008. All drinking-water suppliers are required to register their drinking-water supply, and comply with the relevant sections of the Act.

The Act also makes reference to rural agricultural drinking-water supplies. Their duties under the Act and suitable methods to demonstrate compliance are set out in the Rural Agricultural Drinking-water Supply Guideline.   

The drinking-water Act does not apply to domestic household supplies if the house has its own water supply. Whether to treat tank water is a decision for each owner depending on individual circumstances and preference.


The enactment of this legislation resulted from a concern that the organisation of New Zealand’s drinking-water supplies was not adequate to safeguard communities. New Zealand had been unusual among developed nations in relying almost entirely on voluntary mechanisms to safeguard the treatment and distribution of drinking-water. This represents a risk to public health in two main ways:

  • Disease rates: – Research by the Institute of Environmental Science and Research (ESR) and the Otago School of Medicine shows that rates of sickness are higher in areas where the water does not meet the standards.
  • Risk of disease outbreak – Untreated drinking-water presents a higher risk of disease than treated drinking water. Distributing untreated drinking-water through a reticulated network presents a higher risk of a major disease outbreak. For example Walkerton (pop 4000), Canada, where 7 deaths and 2321 reported cases resulted from E. coli in May 2000 and the more recent Havelock North outbreak in August 2016.

Estimation of the Burden of Water-borne Disease in New Zealand – Preliminary Report
A preliminary study of waterborne disease in New Zealand.

What does the Act do?

The Act does the following:

  1. Requires drinking-water suppliers to take all practicable steps to ensure they provide an adequate supply of drinking-water that complies with the New Zealand Drinking-Water Standards;
  2. Requires drinking-water suppliers to develop and implement water safety plans;
  3. Ensures drinking-water suppliers take reasonable steps to contribute to the protection from contamination of sources from which they obtain drinking-water;
  4. Requires officers appointed by the Director-General of Health to act as drinking-water assessors to determine compliance with the Act and the drinking-water standards
  5. Requires record keeping and publication of information about compliance;
  6. Provides for the declaration and management of a drinking-water emergency;
  7. Provides for penalties for non-compliance.

The Act’s Role in the Management of Drinking-Water in New Zealand

Management of drinking-water in New Zealand can be broken into three main parts.

  1. The environment – The source of the water, either from below ground or from surface catchments, is primarily governed by the Resource Management Act 1991.
  2. Water suppliers – This involves obtaining the raw water from the environment, followed by storage, assessment, treatment, and distribution to consumers. Regulation of this system of abstraction and supply was previously managed through a voluntary regime. However the Act now regulates this system of treatment and distribution which requires water suppliers to contribute towards protecting from contamination all sources from which the drinking-water supplier takes raw water. 
  3. Storage and distribution – Storage and distribution of water in tanks and pipes within buildings up to the point of use (generally a tap) is governed by the Building Act 2004. This Act takes over responsibility for water once it leaves a public networked supply and enters the building-owner’s property (usually at the water toby), and also applies to water distributed within a building from its own self-supply (eg, a roof tank or bore).

The system which governs the ‘second part’ of drinking-water management by water suppliers is administered by the Ministry of Health. This system consists of the following elements:

  1. The New Zealand Drinking-Water Standards. These standards are the reference which water quality is measured against, and provide detailed specifications for drinking-water suppliers, including maximum acceptable values for a range of contaminants and monitoring requirements. Under the Act suppliers must take all reasonably practicable steps to comply with the standards.
  2. Register of Drinking-Water Supplies in New Zealand. This register is maintained by ESR on behalf of the Ministry of Health. The register provides information on who is registered as a drinking-water supplier and gives information about their supplies or sources of water. Inclusion on the register is mandatory for all drinking-water supplies or suppliers serving more than 25 people.
  3. Drinking-Water Online. Drinking Water Online was launched in July 2017 and replaces the old Water Information New Zealand databases. It has been built to provide a comprehensive and complementary service for drinking-water supply management and a tool to support the Ministry, the Public Health Units and the wider industry in continuing to meet their obligations under the Health Act 1956
  4. Water Safety Plans. The Act requires all suppliers serving more than 500 people to develop and implement a water safety plan. Water Safety Plans considers the potential risk to the water supply and identifies ways to manage those risks.  Drinking-water suppliers serving less than 500 people are not required to prepare and implement a water safety plan but may do so voluntarily. Effective water management needs to involve multiple interventions at many levels to protect consumers from receiving contaminated water.
  5. The Annual Report on Drinking-Water Quality is published each year and covers previous year’s compliance for all registered networked drinking-water supplies serving more than 100 people. is . The report describes how drinking-water suppliers met the requirements of the Drinking-water Standards for NZ and how they met their statutory requirements of the Health Act. All recent year’s publications can be found on the Drinking-water publications page.
  6. Guidelines for Drinking-Water Quality Management in New Zealand. The Guidelines complement the Drinking-Water Standards for New Zealand and provides advice for achieving high level of drinking-water quality management. The Guidelines will assist water suppliers to achieve the Standards and are updated on an ongoing basis with new information.
  7. The use of recognised laboratories. The Act requires that only the Director-General of Health-recognised laboratories may be used to carry out tests and analysis of raw water and drinking-water to demonstrate compliance with the Standards.

Drinking-Water Assistance Programme

To help suppliers in small, disadvantaged communities (deprivation index of 7 or above) to provide safe drinking-water, and to assist these communities to establish a safe reticulated supply the Government made available the Drinking-water Assistance Programme.  

The programme began in 2005 and was closed to new applicants in 2015. However some water supply projects funded by the programme are still in progress. Water suppliers who are still upgrading their supplies under this programme can access technical assistance and advice through their local Public Health Units.

Appointment of Drinking-Water Assessors under the Health Act 1956

The Health Act 1956 provides for the Director-General of Health to appoint 1 or more persons or agencies as drinking-water assessors on any terms and conditions that the Director-General considers appropriate (including, without limitation, terms enabling the Director-General to suspend or revoke the appointment in any specified circumstances).  

The Director-General of Health has determined that the following requirements will satisfy him that a person has the experience, technical competence and qualifications to undertake the functions of a drinking-water assessor:

  • at least two years relevant experience in a public health unit or a drinking-water supplier or equivalent;
  • a relevant technical qualification in drinking water;
  • at least six months training and mentoring by a drinking-water assessor (or equivalent); during which core behaviours and competencies have been demonstrated including an understanding of the public health risks caused by unsafe or inadequate drinking-water supplies; 
  • satisfactorily completed the Ministry of Health’s drinking-water foundation training course.

The person must also be accredited to internationally accepted standards for inspection bodies and have in place effective arrangements to avoid or manage any conflicts of interest that may arise.

Appointments of drinking-water assessors will then be subject to the following conditions:

  • completing the NZOQ Management Systems Auditing training within two years of appointment (newly appointed drinking-water assessors);
  • attending a drinking water training course at least every three years (all drinking-water assessors).

Relevant technical qualifications

Examples of relevant technical qualifications in drinking-water are:

  • Diploma in Drinking Water (Drinking-Water Assessment);
  • Diploma in Drinking Water (Water Treatment);
  • Papers 29995, 24906, 29966, 24897, 18456, 18459, 24907, 24912 from any Diploma in Drinking Water (or equivalent from overseas training organisations)
  • Degree in Public Health Engineering
  • Degree in Civil Engineering

Core behaviours and competencies

The Ministry will provide more guidance to prospective employers on the core behaviours and competencies for drinking-water assessors. For example, to be an effective assessor, a drinking-water assessor must be able to develop and maintain effective relationships appropriate between a regulator and the regulated industry including engaging with senior staff at local councils. 

Other DWA appointments

None of the prescribed criteria (current or proposed) prevent the appointment of any individual that the Director-General of Health considers capable of undertaking the role of a drinking-water assessor.  This allows the Director-General to accept individuals who have worked in equivalent roles overseas irrespective of their qualifications. It also allows the Director-General to appoint individuals with a wider range of New Zealand qualifications if they possess equivalent work experience in related industries. 

Register of Drinking-Water Assessors Appointed under the Health Act 1956

Section 69ZX of the Health Act 1956 (as amended by the Health (Drinking Water) Amendment Act 2019 requires the Director-General of Health to maintain a register of individuals who have been appointed as drinking water assessors. 

This register includes the individual's name, employer and the date of their appointment as a drinking water assessor.

The term of appointment for each drinking water assessor is valid until either the drinking water assessor ceases his or her current employment or until it is revoked by notice in writing.

The Director-General of Health has authorised each Drinking Water Assessor to exercise only the following powers set out in the Health Act 1956:

  • the powers conferred in section 69ZP(1)(a) powers of entry;
  • the powers conferred in section 69ZP(1)(b) inspect and copy records;
  • the powers conferred in section 69ZP(1)(c) require information;
  • the powers conferred in section 69ZP(1)(d) supply information and documents;
  • the powers conferred in section 69ZP(1)(e) conduct inspections, surveys, tests;
  • the powers conferred in section 69ZP(1)(f) direct the supply to conduct tests;
  • the powers conferred in section 69ZP(1)(g) take samples;
  • the powers conferred in section 69ZP(1)(h) verify the competence of people performing tests if they are not done by a recognised laboratory;
  • the powers conferred in section 69ZP(1)(i) provide information to the Director-General of Health;
  • the powers conferred in section 69ZQ(1) taking assistants and equipment when exercising power of entry.
Drinking-water assessors
Name Date of Appointment as DWA Employer
(District Health Board)
Sioeli Takataka 28 July 2009 Auckland DHB
Can Lin (Ken) Zhu  02 August 2010 Auckland DHB
Xiaoning (Shaun) Yu 24 September 2013 Auckland DHB
Shiwen Sun 16 September 2014 Auckland DHB
Leslie Breach 16 September 2014 Auckland DHB
Shanshan Li 11 January 2017 Auckland DHB
Grant King 17 October 2014 Bay of Plenty DHB
Braden Leonard 8 February 2018 Bay of Plenty DHB
Kirsty Macleod 28 July 2008 Canterbury DHB
Denise Tully 28 July 2008 Canterbury DHB
Judy Williamson 28 July 2008 Canterbury DHB
Helen Graham 26 June 2013 Canterbury DHB
Fiona Humpheson 25 March 2017 Canterbury DHB
Hayley Proffit 25 March 2017 Canterbury DHB
Amelia Haskell 28 May 2017 Canterbury DHB
Reynold Ball 27 March 2018 Hawke’s Bay DHB
Maree Rohleder 28 July 2019 Hawke’s Bay DHB
Cameron Ormsby 14 August 2019 Hawke's Bay DHB
Barbara Stevenson 3 August 2017 Hutt Valley DHB
Michael Fisher 17 July 2019 Hutt Valley DHB
Peter Wood 31 July 2008 MidCentral DHB
Louise Allen 9 November 2016 MidCentral DHB 
Evan McKenzie 23 February 2008 Nelson Marlborough DHB
David Speedy 27 August 2008 Nelson Marlborough DHB
Keith Turner 17 July 2019 Northland DHB
Zane Jones 27 August 2008 Northland DHB
Jeffery Garnham 28 May 2017 Northland DHB
Rosemarie Nelson 08 February 2010 Southern DHB
Simon Ou 19 February 2009 Southern DHB
Michael Wong 08 February 2010 Southern DHB
Susan Moore 18 December 2014 Southern DHB
Murray Lowe 16 August 2017 Taranaki DHB
Matt Molloy  3 November 2016 Waikato DHB 
Catherine Walker 28 July 2019 Hauora Tairawhiti DHB

Estimated cost of compliance

In the simplest form, the water supply system can be thought about in three parts:

  • Source and pre-treatment infrastructure
  • Treatment plant
  • Distribution system

The estimates of cost of compliance with the Drinking-water Standards for New Zealand are generally based on the cost option for upgrading the system to achieve compliance with bacterial, protozoal and chemical requirements of the Standards. In some cases the lowest cost option may not be the option that would be selected by a community for various reasons, however, because of the fixed cost component of a water supply system, the cost would vary significantly with population size across the country. The following resources address the potential costs of compliance with the Act and the drinking-water standards, and an estimate of the more recent economic cost of the Havelock North drinking-water outbreak.

Drinking-water suppliers should comply with the drinking-water standards. However, the duty to comply with the standards is not inflexible.

In considering the drinking-water standards, there are three levels of what is accepted as compliant:

  1. Meeting the standards exactly as they stand
  2. If (i) is not possible, compliance can be met by implementing an approved Water Safety Plan (WSP)
  3. If both (i) and (ii) are not possible then compliance could still be met by demonstrating to the drinking-water assessor/health protection officer/medical officer of health that all practicable steps have been taken to meet the Standards

‘All practicable steps’ means taking all the steps that are realistic to achieve the required result in that particular circumstance.

Section 69U Duty to take reasonable steps to contribute to protection of source of drinking water

The Health Act 1956 (the Act) protects the health and safety of people by promoting adequate supplies of safe and wholesome drinking water from all drinking-water supplies.

Section 69U(1) of the Act requires that every drinking-water supplier must take reasonable steps to:

  1. contribute to the protection from contamination of each source of raw water from which that drinking-water supplier takes raw water:
  2. protect from contamination all raw water used by that drinking-water supplier.

What is a reasonable step to take depends on the circumstances of the specific supply. This guidance provides water suppliers with examples of actions that may contribute to the protection of raw water sources, and the protection of raw water:

  1. Making submissions on resource consent applications, discussion papers and draft regional and district plans where they may affect raw water or raw water sources, including submitting on proposed discharges from nearby commercial, industrial and agricultural activities.
  2. Making submissions on community outcomes and sanitary services assessments where they may affect raw water or raw water sources.
  3. Take steps to improve catchment management. This includes catchments for surface water, springs, reservoirs and lakes, aquifer recharge zones and aquitard penetration points. The water supplier may be able to do this directly where the catchment is controlled by it; or may need to contribute indirectly, for example where a river, lake or aquifer extends outside the supplier’s boundary. Examples of steps include:
    1. promote riparian planting and fencing along waterways to limit stock access and reduce contaminant run off
    2. promote planting trees and other forms of land stabilisation
    3. promote erosion control to reduce silt contamination of waterways
    4. promote controls on access by the public, stock and vehicles to surface catchments, waterways and aquifer recharge zones
    5. promote the control of pests and other organisms in the catchment that may carry human pathogens
    6. decommission and seal redundant bores operated by the water supplier
    7. ensure existing bores operated by the water supplier are not a groundwater contamination pathway, for example via leakage down the outside of the casing, or due to inadequate back flow protection at the bore head
    8. partner with other stakeholders (for example regional councils, Department of Conservation, landowners, iwi, Forest and Bird, hunting organisations) to share information and jointly work on catchment improvements
    9. promote catchment research and monitoring
    10. promote the use of integrated water resources management.
  4. Additional steps to protect raw water include:
    1. choose construction materials that will not deteriorate allowing pathogens to enter or corrosion products to contaminate the water
    2. maintain sufficient steady pressure in the pipework to prevent pathogen ingress
    3. ensure pipework is maintained, including timely repairs, flushing, leak detection and valve exercising programmes
    4. ensure adequate backflow prevention is provided, tested and maintained.
  5. Develop and implement a risk management plan for catchment, source, storage and raw water protection. This should be part of the water supply’s Water Safety Plan and should include:
    1. a catchment risk assessment that considers sources of contamination, groundwater flows, existing bores and drawdown effects, contaminant attenuation data, and the history of natural events such as algal blooms, floods and droughts
    2. a regular review of the catchment risk assessment, including after a significant event such as an earthquake, landslide, drought, flood or significant change in land use in the catchment.

Further information

Further detailed information about protecting raw water sources can be found in the Guidelines for Drinking-water Quality Management for New Zealand, particularly chapters 3, 4 and 19.

A list of specific examples of steps that a water supplier can take to protect raw water from the point of abstraction to the water treatment plant intake is provided in the ‘Preventative Measures’ sections of the Water Safety Plan Guides for Water Suppliers, particularly Guides in the D2, P1, P2, P3, P4, S1 and S2 series.

Identifying preventative measures is part of the preparation of a Water Safety Plan, see the New Zealand Drinking-water Safety Plan Framework, and the Handbook for Preparing a Water Safety Plan.

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