Frequently Asked Questions

Is there planned indirect or direct potable reuse in Australia?

It is now also possible for advanced treatment technology to produce safe drinking (potable) water. In several  countries wastewater is recycled for potable reuse via groundwater injection (e.g. Factory 21, Orange County,  California, USA which came online in June 2008  or where  it is added directly to surface reservoirs (e.g. NeWater, Singapore). Such planned indirect or direct potable reuse is not currently  practiced in Australia, although it is being considered by some councils with severe water shortages.

Why use recycled water as a potable source?

Potable reuse has the capacity to readily utilise all the wastewater generated; water demand will always be  greater than the wastewater supply because the wastewater flow to the treatment facility is a subset of the total  potable water used in the house and garden..

What are the key potential health risks?

If water is recycled from sewage treatment plant effluent, it could contain a large range of gastrointestinal  pathogens including viruses, bacteria, protozoa and helminths. If treated to be fit for drinking none of these  pathogens will compromise human health. However, the treatment process must ensure adequate removal (see National Water Commission drinking water standards) as a number of gastrointestinal  pathogens are capable of causing severe illness or death. It is worth also noting that, many people who are  exposed will not develop any symptoms, and the majority of persons who are affected are likely to suffer only  short-term, mild to moderate gastroenteritis without long-term health effects.

Common grouping for pathogens discussed are:

Viruses - over one hundred and forty types of human enteric viruses are known to exist, and these are  classified based on morphological, physico-chemical, genetic and antigenic properties.

Bacteria - a wide range of pathogenic bacteria capable of causing human illness are found in human  sewage.

Protozoa - sewage contains a range of pathogenic protozoa. Cryptosporidium and Giardia are likely to  be the most prevalent species of pathogenic protozoa found in sewage in Australia.

Helminths - these are parasitic worms which are endemic in many areas of the developing world but are  relatively rare in developed nations. There are two major divisions of helminths, the roundworms and  the flatworms (including tapeworms).

Further Information and resources

Australia

National Water Commission Waterlines Report No 2 on Using recycled water for drinking

CSIRO Report To drink… or not to drink? Predicting community behaviour in relation to wastewater reuse. This report outlines the results of a three-year investigation which aimed to develop a measurement of prediction of community behaviour in relation to the reuse of different wastewaters for different uses.

Australian Government Department of Health and Ageing - Review of Health Issues Associated with Potable Reuse of Wastewater - Final Report  

Hastings Council, NSW- brochure on Indirect Potable Reuse (pdf)

International

National Academies Press Online books - Issues in Potable Reuse The Viability of Augmenting Drinking Water Supplies With Reclaimed Water - Committee to Evaluate the Viability of Augmenting Potable Water Supplies With Reclaimed Water by the Water Science and Technology Board and Commission on Geosciences, Environment, and Resources, National Research Council 1998

CIWEM Information Resources on Direct and Indirect potable reuse

EUREAU is the European federation of national associations of drinking water suppliers and waste water services.

Dioxins, Furans and PCBs in Recycled Water for Indirect Potable Reuse – Research article in International Journal of Environmental Research and Public Health - 2008

See also our section on Managed Aquifer Recharge, as it also relates to indirect potable reuse