Greywater Reuse Compliance in New Zealand and Overseas

This paper discusses the regulatory compliance of greywater reuse and disposal in a New Zealand context. Comparisons with overseas regulations and compliance allow us to develop recommendations to improve compliance, resulting in a reduced risk to environmental and public health. 

The “Greywater-wise” research program at ESR has been investigating the drivers for greywater use in an NZ context. Diversion of greywater for disposal purposes is common and often unregulated - compliance with regulatory requirements for greywater disposal is low. 

Overseas, countries such as the USA, Canada and Australia have varying state/territory/regional requirements for greywater reuse. This is often appropriate as these are large, geographically variable countries, with defined internal divisions (e.g. state). New Zealand is a much smaller country and little is gained by all 16 regions having separate and conflicting regulations for greywater reuse. 

We would recommend that in order to improve compliance, information regarding greywater reuse and disposal risks needs to be more readily accessible to the homeowners. There should also be an attempt to improve the consistency of information and requirements between different regulatory authorities.