Quality of Recycled Water
Recycled water is fully treated and can be safely used for a variety of purposes appropriate to the level of treatment it has undergone. Melbourne Water currently supplies Class A and Class C recycled water from its treatment plants in accordance with government environmental and health and safety guidelines.
Classes of Recycled Water
In Australia, recycled water is classified according to its quality and range of uses.
Class A
This is the highest quality of recycled water and is achieved after a tertiary treatment process combined with pathogen removal.
The Department of Human Services has classified Class A recycled water as safe for use on irrigation for food crops - including those eaten raw. The Department of Human Services requires an extensive verification process to ensure Class A water can be guaranteed. EPA Victoria also supports its use.
Class A recycled water has the widest range of uses including:
- residential garden watering
- closed system toilet flushing
- process/cooling water for industry
- fire protection stores and reticulation systems
- irrigation of municipal parks and sportsgrounds
- water for contained wetlands or ornamental ponds
- food crops that are consumed raw or sold to consumers uncooked or processed
- all of the uses listed for classes B, C and D
Class B
A secondary treatment process, combined with some pathogen reduction is used to produce Class B recycled water. With strict management practices it may be used for the following:
- irrigation of dairy cattle grazing fodder
- livestock drinking water (not including pigs)
- wash down water for dairy sheds and stockyards (not including milking equipment)
- urban (non-potable) uses with restricted public access
- closed industrial systems
- all of the uses listed for classes C and D
Class C
A secondary treatment process combined with minor pathogen reduction is used to produce Class C recycled water. With strict management practices it may be used for the following:
- cooked/processed human food crops
- selected (raw/unprocessed) crops not directly exposed to recycled water (eg. apples)
- grazing/fodder for cattle, sheep, horses, goats etc.
- grazing for dairy cattle (subject to a five day withholding period after irrigation)
- urban (non-potable) uses with restricted public access
- closed industrial systems
- all of the uses listed for Class D
Class D
A secondary treatment process is used to produce water of this quality. Class D recycled water may be used for the following uses:
- non food crops such as woodlots, turf growing and flowers