Greywater

Installed Simple Greywater Diverter System

Greywater

During 2005 we undertook a preliminary study into the local reuse and recycling of greywater in Melbourne. Different systems were examined and peoples experiences with greywater was looked at. A summary of the investigation findings can be found here. The full version can be purchased or an electronic version obtained by phoning Sustainable Plumbing Solutions P/L.

Individual households can contribute towards reducing water consumption and wastewater volumes by installing small greywater reuse or recycling systems and using the resultant non-potable water for garden irrigation.

There has been a large body of research carried out into the barriers and benefits of water recycling in Australia. In most cases these studies have focused on broad scale recycling of waste water and not on the benefits and barriers of domestic on-site greywater recycling.

Greywater forms a large portion of wastewater and can be either light greywater from the shower, bathroom sink and laundry, or dark greywater from the kitchen. It is estimated that an average household produces 430L - 567L a day of greywater (2 adults, 2 children).

Greywater can be used for different purposes ranging from landscape or agricultural irrigation, to industrial and domestic use. The suitability of greywater for these purposes depends on the quality of the greywater.

Our understanding of the current legislation is that untreated greywater can be diverted from the house and used for subsurface garden irrigation only in times of drought, so long as it is not stored. Legally it cannot be used in above ground irrigation systems (microsprays, pop-up or shrub sprays), or in the house (including toilet flushing). We recommend that only light greywater be diverted to the garden.

Greywater which has been treated to a Class A standard can be stored and used in any type of irrigation system as well as for flushing toilets.
Suitable Systems

The suitability of different greywater systems depends on the proposed use for the greywater and also the layout of the existing pipes. Not all houses can be retrofitted with greywater systems, as in some houses it is impossible to separate the greywater from the blackwater (toilet waste).

If you would like further information please call Brent us on 03 9877 6208.
Plumbing regulations in Victoria and NSW state that any work involving alteration to the sewer or stormwater system must be carried out by a licensed plumber. These systems should not be installed by the home handy man.

In many cases, existing irrigation systems are not suitable for greywater use. If you require assistance with designing a greywater irrigation system please contact Botanical Traditions.