Drinking water standards specify the desired quality standards for water used for drinking purposes. The Drinking-water Standards for New Zealand (DWSNZ) is reinforced by Section 69A of the Health Act 1986 which advocates for the provision of potable drinking water to people of New Zealand and that the suppliers observe compliance with the desired drinking water standards. The DWSNZ was developed by the Drinking-water Advisory Committee in collaboration with working groups. The standards define the maximum acceptable value (MAVs), which stipulates the quality specifications for drinking water. MAVs specifies the highest concentration of a substance in drinking water for which it is considered to safe or not harmful to human health when a person takes 2 litres a day for 70 years. Substances considered include microbial, organic, inorganic, radiological, and aesthetic determinants. MAVs are defined based on guidelines provided by the World Health Organization (WHO). It also specifies the compliance criteria which defines monitoring requirements and corrective actions to be taken in case the maximum acceptable values are violated. The supply of water is further regulated under the Local Government Act 2002.
In New Zealand, drinking water standards apply to water sources, treatment plants and distribution systems. Compliance is therefore needed in all these components. Non-compliance is reported in the case of extreme E. coli concentrations, alarming levels of pathogens, cyanotoxins or chemicals at levels which are a threat to human health and illness in the society due to waterborne diseases. The Drinking-water Standards for New Zealand, therefore serves to protect human health by ensuring the water provided is safe. It applies to all parties involved in the production and distribution of drinking water. It provides guidelines and requirements for compliance as well as the necessary remedial actions in case of non-compliance.
Drinking-water Standards for New Zealand 2005 (Revised 2018)
A quick reference source for New Zealand Standards and Guidelines is available on the ESdat.net website.
Reference
Ministry of Health (2018). Drinking-water Standards for New Zealand. Wellington: Ministry of Health.