Recycled water

Recycled water is wastewater (residential sewage and industrial trade waste) treated and disinfected to a safe standard for beneficial reuse.

We aim to maximise the beneficial use of recycled water to foster liveable communities with secure and sustainable water supplies.

Benefits of recycled water

Recycled water is:

  • safe, high-quality and always in supply, regardless of climate or population factors
  • not subject to water restrictions
  • priced cheaper than drinking water.

Treating and reusing wastewater:

  • protects natural sources from overuse
  • reduced the demand on drinking water
  • reduces the amount of groundwater needed for agriculture
  • reduces the amount of treated wastewater discharged to waterways and the ocean
  • can reduce fertiliser application due to nutrients remaining in the recycled water.

Recycled water production

From time to time our recycled water plants need to be taken offline for maintenance.

During the times plants are offline, recycled water customers will receive potable water – charged at the same rate they pay for recycled water – through the recycled water network.

Even though during these times the water is from the potable supply, the water within the purple pipe system, and other recycled water networks, is not fit for drinking due to the way the infrastructure is operated, and as such must be treated by customers as if it is recycled water.

Treatment and classes of recycled water

All of our water reclamation plants treat wastewater using a combination of mechanical and biological processes to produce recycled water to Class C standard or better. Some facilities employ additional treatment to produce Class A recycled water – the highest grade of recycled water.

Recycled water is classified into four classes, depending on the level of treatment and its suitability for end use.

Class D is the lowest grade of recycled water. It is certified for use on certain non-food crops such as instant turf, woodlots and flowers. We do not produce Class D recycled water.

Class C recycled water can be used for a number of uses including for certain human food crops, livestock grazing and fodder, and the irrigation of public spaces such as sporting ovals or golf courses. There are restrictions around human contact. All of our water reclamation plants produce Class C recycled water or better.

Class B is a higher grade of recycled water with fewer restrictions on human contact. It is suitable for certain agricultural uses such as dairy cattle grazing. While some of our facilities do produce water to a Class B standard, we specify it to Class C level.

Class A is the highest grade of recycled water, and the only grade certified for residential use. Class A recycled water can be used for toilet flushing, garden watering and firefighting. It can be used to irrigate all food crops, as well as all of the approved uses for classes B, C and D. Class A recycled water is currently produced at the Black Rock water reclamation plant and Northern Water Plant.