Frequently Asked Questions: Annual Review of Drinking-Water Quality in New Zealand 2008/09
- What is the Annual Review of Drinking-Water Quality in New Zealand 2008/09?
The Ministry of Health undertakes a yearly microbiological review of the quality of drinking water. The Annual Review of Drinking-Water Quality 2008/09 report covers the financial year from 1 July 2008 to 30 June 2009. The information was obtained from public health units of District Health Boards using questionnaires on the performance of water suppliers.
In 2008/09, the Register of Community Drinking-Water Supplies in New Zealand listed 2,339 distribution zones and 2,296 water treatment plants, and covered an estimated 89% of the New Zealand population. The rest of the population have their own water supply, either from a roof tank or bore.
- Why is the report on the Annual Review of Drinking-Water Quality being published?
The Annual Review of Drinking Water-Quality in New Zealand 2008/09 is the latest in a series of annual reports that were first published in 1994.
The report is being published in compliance with of section 69ZZZB of the Health Act 1956 [as amended by the Health (Drinking Water) Amendment Act 2007], which requires the Director-General of Health to prepare and publish an annual report on drinking water before 1 July each year.
The report informs the New Zealand public of the quality of their drinking-water supplies, by providing an overview of drinking-water quality in each district health board area and a summary of drinking-water in each area, among other information. It is also hoped that publication of the report will encourage water suppliers to improve monitoring.
- The 2008/09 report shows that the proportion of the NZ population whose drinking water complied with the bacteriological criteria of the drinking water standards was 80 per cent. This represents a 3 per cent decrease from the previous survey. What are the factors behind the drop in overall compliance?
There are two reasons behind the drop in compliance: (1) about 1% of the drop is due to a decline in monitoring by water suppliers. (2) the other 2% is a result of the failure by some water suppliers to update the population on registered water supplies to reflect the increase in the New Zealand population.
However, most water supplies serving large population areas (urban areas and towns with populations of more than 5000) are fully compliant with the drinking water standards.
Despite a small decrease in monitoring by water suppliers, the review found a decrease in E.coli contamination and an increase in the number of water suppliers using recognised laboratories for compliance monitoring.
- 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 viruses leads to the potential for outbreaks of disease.
The release of the annual report on New Zealand’s drinking-water quality is part of an organised campaign started in 1992 to improve the quality of the country’s drinking water. The 2008/09 review covers the third year that the microbiological and chemical quality of drinking water was assessed using the Drinking-Water Standards for New Zealand: 2005.
The following have also been established or developed and are being implemented to ensure New Zealand’s drinking water remains safe:
- External surveillance by Health Protection Officers
- A register of Community Drinking-Water Supplies
- Public Health Grading of Community Water Supplies
- Register of Ministry of Health-recognised laboratories for drinking-water compliance test
- National electronic water quality information database
- Public Health Risk Management Plans – each water supply is recommended to be covered by a quality assurance programme contained in a public health risk management plan
- Guidelines for Drinking-Water Quality Management in New Zealand
- Drinking water standards for New Zealand (since 1984)
The Health Act 1956 was amended in 2007 to progressively require water suppliers to prepare Public Health Risk Management Plans and to do “all practicable steps” to comply with the drinking water standards. Due to the economic situation and to give water suppliers more time to comply, the Government in 2009 extended the timelines in the Act by three years.
- The report noted that monitoring for E.coli ceased in a further 125 water supplies during the 2008/09 period. Why did monitoring ceased in these supplies?
The reasons will vary for each drinking water supply and where appropriate, the public health units will take it up with the water supplier. Note that 93 of these supplies are private supplies (maraes, camping grounds, country clubs, etc) and may not see the point in monitoring when they know there is likely to be faecal contamination in the supply.
- During 2008/09, the number of Local Authority-run zones in which bacteriological transgressions were not followed up by the water supplier with adequate corrective action remains high at 32. Why were the transgressions not followed up?
The reasons why the water supplier did not adequately follow up positive samples with adequate corrective action will vary from supply to supply. When this is known, the Drinking Water Assessors in public health units discuss this with the supplier and ensure adequate corrective action is taken.
This finding does not mean that all 32 supplies did not take any action at all but rather, that the action was inadequate.
- Five of 12 hospitals and health services with their own water supplies were bacteriologically non-compliant in 2008/09. (All 10 hospital/health services surveyed in 2007/08 were compliant with the standards.) Why were these five non-compliant?
The five hospitals and health services that did not comply with the standards in 2008/09 were:
- PrincessMargaretHospital in Christchurch – failed to follow appropriate procedures following E.coli contamination due to communication issues between the hospital and the laboratory. These have now been resolved.
- Te Puia Springs Hospital and Village in Gisborne – E.coli contamination. Their Public Health Risk Management Plan and Capital Assistance have been approved, and are now in the early stages of implementation.
- Waiheke Health Trust on WaihekeIsland – failed to report E.coli contamination to the Drinking Water Assessment Unit-Auckland (DWAU-Auckland).
- Aotea Health, GreatBarrierIslandAnd
- Great Barrier Community Health – water supplies are not monitored and therefore are registered as non-compliant.
Both Aotea Health and Great Barrier Community Health have been offered assistance through the local Drinking Water Assessment Programme. They are small island health centres which have a similar level of water supply (usually, a roof tank) to the houses on the Island.
- Seventy-one per cent of the 597 schools and early childhood centres conducted some bacteriological monitoring last year; of these, 118 supplies or 20 per cent complied with the bacteriological criteria of the drinking water standards, which continued the improvement in recent years. Who is responsible for the safety of school drinking water supplies?
The improvement in compliance of school supplies has continued, with 20% of schools complying in 2008/09.
The safety of school drinking water supplies is the responsibility of each school’s Board of Trustees. Where a major upgrade is necessary, such as a new bore, the Ministry of Education will undertake the work under its capital works programme.
Many schools have installed ultraviolet treatment in conjunction with cartridge filtration and the drinking-water standards recognised UV treatment as a legitimate way of meeting protozoa compliance when the drinking water standards 2005 came into force.
Furthermore, the Ministry of Health has contracted district health boards to work with water suppliers to ensure and encourage compliance with the drinking water standards.
Most of the schools with their own water supplies are small rural schools. Although the Ministry of Education provides capital assistance for treatment systems if required, monitoring is the schools’ responsibility. Many schoolchildren will be on home supplies of similar quality and the Boards prefer to spend their funding on other priorities.
- The estimated proportion of the population supplied by protozoal-compliant plants in 2008/09 was 63 per cent. What is the reason behind the drop in compliance?
The drop is not a decline in overall protozoal compliance but a result of removing double-counting by many treatment plants supplying multiple zones. This year’s protozoal compliance figure is more accurate than those calculated in the past.
To estimate the population that may be exposed to protozoal contamination, ESR previously listed the maximum population that compliant treatment plants were able to supply. However, many large communities are supplied by several treatment plants which, if combined, are able to supply more people than is in the community, resulting in double counting. ESR has revised their method of collating the information to remove this double counting.
ENDS