Annual Report on Drinking-water Quality 2015-2016

Published online: 
12 April 2017

The Report describes the drinking-water quality of all registered networked drinking-water supplies that served populations of more than 100 people. It describes how these supplies met the requirements of the Drinking-water Standards for New Zealand and their progress towards meeting the requirements of the Health Act 1956 between 1 July 2015 to 30 June 2016.

Summary of findings

The report shows that for registered drinking-water supplies that served populations of more than 100 people:

  • 3,699,000 people (97.6 percent) received drinking-water which met bacteriological standards, which is the most important criteria.
  • 3,109,000 people (82.0 percent) received drinking-water which met the protozoal standards.
  • 3,732,000 people (98.4 percent) received drinking-water which met the chemical standards.
  • 3,513,000 people (92.7 percent) received drinking-water from supplies that had a water safety plan implemented.
  • 3,032,000 people (80.0 percent) received drinking-water which met all the requirements of the standards. 

In 1995, the Ministry of Health set a target of 95 percent compliance with bacterial and chemical Standards by drinking-water supplies serving over 500 people. Since then compliance rates have changed by small amounts each year but overall water suppliers serving more than 100 people exceed the 95 percent target.

Prompt remedial action also needs to be taken by drinking-water suppliers in the event that monitoring reveals contamination of the water as pathogens can rapidly cause illness. The Report shows that almost all drinking-water suppliers undertook remedial action where monitoring revealed contamination of the water, other than 14 small supplies serving approximately 0.2 percent of the report population (24,000 people). This non-achievement by small supplies may reflect the increasing per capita cost of maintaining effective bacteriological treatment. Similarly, for those supplies that have not met protozoal compliance, it is because adequate barriers are not yet in place to ensure the drinking-water is free of protozoa, in these supplies the protozoa risk is unknown.

Water safety plans are developed and implemented by drinking-water suppliers to identify what risks may exist for a water supply and how to manage these risks – or what action to take if anything does go wrong. The Report shows that over 92.0 percent (3,513,000 of report population) received water from supplies that had implemented a water safety plan.

This Report is the latest in a series of annual reports there were first published in 1994. To access previous reports see Drinking water resources.

Other initiatives to raise overall compliance with the Standards include:

Publishing information

  • Date of publication:
    12 April 2017
  • ISSN:
  • HP number:
  • Citation:
    Ministry of Health. 2017. Annual Report on Drinking-water Quality 2015-2016. Wellington: Ministry of Health.
  • Ordering information:
    Only soft copy available to download
  • Copyright status:

    Owned by the Ministry of Health and licensed for reuse under a Creative Commons Attribution 4.0 International Licence.

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