“We’re trying to develop a practical, robust, repeatable testing method for greywater treatment technologies to meet

Australian guidelines for recycled water,” CSIRO water technologies development chemist Melissa Toifl says.

“Technology manufacturers are frustrated because every time they try to market their product in a different State they have to go through the whole approval procedure again.

“We’re hoping this protocol will eventually form a national Standard that everyone works to, in order to make it easier for technology manufacturers and consumers to adopt the technology.”

The project, partly supported by the Smart Water Fund, is a joint initiative of Melbourne’s water businesses and the Victorian Government, and the CSIRO Water for a Healthy Country Flagship. It began with the development of ‘synthetic’ greywater.

“We needed something that was consistent so the background for testing wasn’t altered and all variables were controlled,” Melissa says.

“It was also important that it mimicked real greywater.

“The synthetic greywater that was developed contains basic everyday products that people use in the bathroom and laundry – soap, toothpaste, washing powder and other personal care products.”

This formulation allows for controlled testing of greywater treatment technologies and provides a baseline for performance comparison.

Several greywater treatment technologies were obtained, from which the protocol was developed. Testing began with a traces study that outlined exactly how each technology works. Chemical analysis then established the basic working order.

“We do the chemical testing to ensure the technology removes the normal chemicals that are present in greywater –nitrogen, phosphorus, suspended solids, etc,” Melissa says.

“Once its performance in this area is satisfactory we assume it is working correctly.

“The greywater testing technologies are then subjected to a series of challenge-based tests. In a normal situation it would get a certain number of micro-organisms – including bacteria and viruses – coming through steadily day by day.

“What we do is hit the system with a really high dose of micro-organisms and pathogens and see if it can remove those – and that’s basically what the protocol entails.”

In essence, the protocol will measure whether a greywater treatment technology, in a challenged situation, can meet Australian guidelines for recycled water.

“The protocol won’t bring water to that standard; it will test whether it is at that standard.”

But will it encourage manufacturers to produce better-quality technologies?

“That is a tricky one. Theoretically all technologies would be aiming to provide a high quality of water. However, the greywater testing protocol or a national Standard may find that some systems aren’t able to cope with shock doses of micro-organisms – which might mean a tiered system will result.”

The protocol is the first of its kind in Australia, and Melissa expects it will lead the way for a national approach to testing and regulating greywater treatment technologies.

In September, CSIRO was invited to present its findings at the International Water Association World Water Congress in Vienna, Austria.

“There has been significant interest nationally and internationally in applying the outcomes of this project, so presenting the research to an international audience was invaluable,” Melissa says.

“We hope it may even become an internationally recognised and used protocol.”