Producing recycled water

Melbourne Water produces high-quality Class A recycled water at our Eastern and Western treatment plants, following strict regulatory guidelines.

Key facts

  • The highest grade of recycled water in Victoria is Class A, which can be used for non-drinking purposes.
  • Melbourne Water is able to produce the largest amount of Class A recycled water in Australia.
  • Our advanced treatment technologies remove more than 99.999% of pathogens from wastewater.
  • We use a quality control process which is common throughout the food industry, called Hazard Analysis and Critical Control Points (HACCP).
  • Highly treated wastewater is recycled for a range of non-drinking uses, helping to save our precious water supplies in an uncertain climate.

Standards and guidelines

We follow several guidelines for producing recycled water, including those set by:

These have different approaches to regulating quality. Some, like EPA Victoria’s, specify classes of recycled water based on microbiological quality. Others, like the federal government’s Australian Guidelines for Water Recycling, require us to treat it to a standard that makes it safe for its intended use.

Production process

Each of our two treatment plants uses processes specially designed to suit the characteristics of the plant and the incoming wastewater.

Eastern Treatment Plant

The Eastern Treatment Plant is one of the few plants in the world that can treat all incoming wastewater to a standard suitable for reusing, rather than only a small percentage.

In 2012, it was upgraded to include an advanced tertiary treatment process, involving filters, ozone, ultraviolet light and chlorine.

Western Treatment Plant

The Western Treatment Plant was the first plant in Victoria to produce Class A recycled water. This process makes use of use of our existing lagoon system, which produces Class C water in 30 to 35 days.

To reach Class A standard, ultraviolet light and chlorine are used to further disinfect the water. Some of this is used to water crops, parks and gardens, whilst some is further processed to reduce its salt before it can be supplied to homes.

Sewer mining

Sewer mining recycles water at a local scale by removing sewage from mains and treating it on-site – before it reaches the treatment plant. This produces high quality recycled water that can be used nearby, while waste by-products are returned to the sewerage system.

Sewer mining plants are usually small and use a combination of conventional filtration, biological, membrane and disinfection processes.

Accessing recycled water

After recycled water is produced, it is supplied to Melbourne's retail water companies – City West Water, South East Water and Yarra Valley Water – who distribute it through their pipe networks to homes and businesses.

As a general rule, only areas near our treatment plants can access recycled water. Areas currently using it include the:

  • Werribee Tourist Precinct — including the golf club, zoo and mansion
  • Werribee Employment Precinct — a 900-hectare site for research and learning institutions
  • Eastern Irrigation Scheme, Cranbourne — supplies more than 80 customers with water for horticulture, irrigation and industrial processes
  • Cranbourne housing estates.

To find out if you can access recycled water, contact your local water retailer.

Last updated:
14 July 2019