Greywater technology
Greywater is generated by any occupied premises. The water can be recycled to provide a reliable source of water for activities that do not require drinking water quality (e.g. irrigation, toilet flushing, and washing).
The characteristics of greywater produced by a residential premise will vary according to the number, age, lifestyle, health status, and water usage patterns of the household’s occupants.
The levels of treatment affect the general uses of greywater, how it is stored, the quality and the approvals required to recycle this water. The treatment levels required and allowed uses vary across Australia with national and state guidelines.
In Australia, all modifications or installation of permanent greywater diversion devices and/or greywater treatments systems must be carried out by licensed plumbers. This is regulated by the specific state plumbing code or Australian Standard (AS/NZS 2003b) which requires that any work conducted on the water supply, sanitary plumbing or drainage systems is to be carried out by a licensed plumber.
The use of greywater is usually regulated by state or territory government environmental, health, and/or water authorities. Local councils may also have special requirements for the installation of greywater systems on sites within their area, such as council overlays. Generally, if it goes down the waste outlet in a household’s plumbing it requires a licensed plumber to install a Greywater Diversion System and/or a Greywater Treatment System. Greywater diversion devices do not treat greywater.
Greywater systems available in Australia
Greywater systems available in Australia include:
- Greywater treatment systems
This system treats water to Class A standard or so it fit for use in the house. This means that the treated greywater can be stored and used in the home, for toilet flushing or laundry washing as well as be connected to a greywater irrigation system. - Greywater diversion permanent
Permanent diversion systems usually have a coarse filter of some nature and a pump that eliminates excess water to sewer if not used within 24 hours. This water is used for drip irrigation and is not suitable for spray irrigation or for use in the home. - Greywater diversion temporary
Temporary diversion systems such as a bucket or pipe usually have no treatment.
However, if you are away on holidays and not using any mains water none of these systems will be supplied with greywater.
Working safely with greywater
There are a number of dos and don’ts to be taken into account when installing and using a greywater system. These vary depending on the type of system used and the level of treatment. Key considerations for greywater use and for installation of greywater systems are outlined in the "Working safely with greywater" section of the website.