This report describes the microbiological and chemical quality of water in New Zealand drinking-water supplies serving populations of more than 100 people, and progress towards meeting the requirements of the Health Act 1956, from July 2012 to June 2013.
The report comprises the level of compliance for each category of water supplier (large, medium, minor, and small) with sections 69S to 69ZC of the Health Act 1956, and the drinking-water standards.
In 1991, the Ministry of Health set a target of over 95 percent compliance with bacterial and chemical standards by drinking-water supplies serving over 500 people. Compliance with all drinking-water standards increased by 0.2 percent to 76.9 percent in population terms during 2012/13, bacterial compliance was 96.7 percent and chemical compliance was 95.3 percent. These bacterial and chemical compliance rates are also across all water supplies serving over 100 people, including small drinking-water supplies which generally experience greater difficulty in achieving compliance. There was a slight decrease in protozoal compliance, from 79.8 to 79.2 percent.
Frequently asked questions
Is my drinking-water safe?
During the reporting period over 2.9 million New Zealanders on reticulated supplies serving over 100 people were provided with drinking-water that met all the Drinking-water Standards and, therefore, was demonstrably safe.
In the early 1990s, the Ministry of Health set a target of 95 percent compliance with bacterial and chemical standards by drinking-water supplies serving over 500 people. In this reporting period bacterial compliance was achieved for 96.7 percent of the population and chemical compliance for 95.3 percent of the population (on all supplies serving over 100 people). There was a slight decrease in protozoal compliance, from 79.8 to 79.2 percent of the population in this reporting period.
For those people on supplies that had E.coli or chemical levels above the maximum acceptable values, remedial actions were taken immediately in supplies serving 98.5 percent of the population covered in the report. Water supplies that did not comply due to inadequate monitoring (a technical non-compliance) were not necessarily unsafe, but monitoring is important to be sure water is safe. Likewise, for those supplies that have not met protozoal compliance because adequate barriers are not yet in place to ensure the drinking-water is free of protozoa, the risk is also not known.
Water safety plans (formerly known as public health risk management 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 something does go wrong. During the reporting period, 93.1 percent of the reported population received water from supplies that were implementing a risk management plan (1.7 million people) or had an approved plan ready to implement (1.8 million).
What is the Annual Report on Drinking-Water Quality in New Zealand 2012/13?
The report describes drinking-water quality, and progress towards meeting the requirements of the Health Act 1956 and the New Zealand Drinking-Water Standards, for all registered community drinking-water supplies that served populations of more than 100 people from July 2012 to June 2013 (covering a total of 3.8 million people).
Why is the report on the Annual Review of Drinking-Water Quality being published?
The Annual Review of Drinking-Water Quality in New Zealand 2012/13 is the latest in a series of annual reports that were first published in 1994. Publishing the report each year fulfils a statutory requirement of the Ministry.
The report includes information on measures other than the Standards. Why has this information been included?
The Health (Drinking Water) Amendment Act 2007 amended the Health Act 1956 and came into force in 2008. It included a number of duties for water suppliers, including taking all practicable steps to comply with the drinking-water standards. The Act requires information on water-suppliers compliance with their duties to be included in the report.
What steps are being taken to raise overall compliance with the drinking-water standards?
The government is committed to ensuring that all New Zealanders have access to safe drinking-water. Failure to maintain high microbiological standards by not managing bacteria and protozoa leads to the potential for outbreaks of disease. The following initiatives have been established or developed and are being implemented to ensure New Zealand’s drinking-water remains safe:
- drinking-water subsidies to assist small, disadvantaged communities to have access to safe drinking-water – further information available from Applying for a Drinking-water Subsidy: Guidelines for applicants and district health board public health units
- external surveillance of drinking-water supplies by drinking-water assessors and health protection officers from local DHB public health units
- publication of a Register of Community Drinking-Water Suppliers
- publication of a Register of Ministry of Health Recognised Laboratories for drinking-water compliance tests
- maintenance of a national drinking-water quality information database
- publication of Guidelines for Drinking-Water Quality Management in New Zealand
- publication of Drinking-water Standards for New Zealand (since 1984)
- water suppliers are progressively required to prepare Public Health Risk Management Plans and to take ‘all practicable steps’ to comply with the drinking-water standards.
How does compliance with the drinking-water standards compare with last year?
During the reporting period over 2.9 million New Zealanders on reticulated supplies serving over 100 people were provided with drinking-water that met all the Drinking-water Standards. Compliance with all drinking-water standards increased by 0.2 percent to 76.9 percent in population terms during 2012/13. Achievement of the bacteriological standards was at 96.7 percent (up from 95.8 percent) and achievement of the chemical standards was at 95.3 percent, (a decrease from 95.7 percent) and so continue to exceed the Ministry of Health’s targets. The drinking-water standards, based on the World Health Organization guidelines for drinking-water quality, give highest priority to health risks arising from microbial contaminants because they can lead to rapid and major outbreaks of illness. There was a slight decrease in achieving the protozoal standards, which was at 79.2 percent of the population in this reporting period (a decrease from 79.8 percent).
What has caused the small drop in protozoal and chemical compliance?
The slight decrease in achievement against the protozoal Standards was due to three large supplies which achieved the protozoal Standards in the 2011/12 period but not within the current reporting period. This number was off-set slightly by two large supplies achieving the Standards in this reporting period that did not achieve them in the last report, and an overall improvement in all other sized supplies, including a 4.8 percent rise in achievement by medium supplies. The reasons the three supplies which achieved the protozoal Standards last report but not this report were due to what is described as technical failures as protozoa is not monitored, unlike E.Coli.
A decrease in achievement against the chemical Standards was also noted. Again, this was mainly driven by zones which met the chemical Standards last report but not this report. There were 15 zones in this category serving a total population over 58,000 and over 50 percent of these were due to inadequate monitoring rather than exceedences of the maximum acceptable values.
Of the people in non-compliant zones, how many are due to poor monitoring rather than poor water?
Over 60 percent of the population on all the supplies which failed the bacteriological standard in this reporting period did so because of insufficient monitoring rather than due to E.coli transgressions. Monitoring is important for determining whether supplies meet appropriate standards.