Greywater Diversion Systems

Managing unused greywater

Greywater diversion should be for beneficial use only; it is not an option for easy disposal of wastewater. Owners and residents must recognise that a greywater diversion device must be treated like a garden tap (i.e. turned on only when the garden needs water). If the greywater diversion device is turned on all the time, there is a high risk of detrimental impact to the environment (plants, soil, and water-bodies) and to residents’ health.

Any greywater that cannot be immediately reused for sub-surface irrigation at the residential premises must be diverted to the sewer. Diverted untreated greywater is not suitable for use in the house for toilet flushing or washing.

Source and application of Untreated Greywater

For a greywater diversion device, the sources of greywater include:

• washing machines
• laundry tubs
• showers
• baths

Temporary Greywater Diversion

A temporary greywater diversion system is a temporary arrangement that diverts greywater for immediate use. Examples of this are washing machine wastewater pumped directly from the washing machine (rinse cycles preferred), collection of shower water in buckets prior (while warming up) or during showering, and siphoning water from laundry troughs.

The most important aspect of a temporary greywater system it that the greywater should be captured before it enters the household drainage system.

There are a number of temporary greywater diversion system options that can be used when sourcing and applying this greywater:

• A bucket – The simplest form of temporary greywater diversion is using buckets to capture and transport water from baths or washing machine troughs to the lawn or garden. Remember to look after your back and don’t carry buckets that are too heavy (10 L of water = 10 kg).
• A hose that is temporarily connected to the washing machine outlet pipe and directs this water to the lawn or garden
• A portable sump pump with a hose connected that can be used to pump bathwater or laundry water (caught in the trough) when they require emptying
If using a hose; make sure it is purple, indicating it contains recycled water or greywater, and store it in a safe place so it is not misused. Use a hose dedicated for greywater use only.

Permanent Greywater Diversion

A permanent greywater diversion system diverts greywater after it passes the plug hole to a holding tank with little treatment (usually some sort of simple filter system) . The water must be used within 24 hours or automatically pump to sewer. This is known as a Permanent Greywater Diversion System. This system can only be installed by a licensed plumber.

A permanent greywater diversion system incorporates the following features:

• a hand-activated valve
• a switch or tap that is fitted to the outlet of the waste outlet pipe of the plumbing fixture (e.g. a washing machine)
• a coarse filter for screening out solids and oils/greases
• non-storage surge attenuation
• an overflow device
• a subsurface (usually) garden irrigation or distribution system.

It is the responsibility of the individual and plumber who undertakes these activities to obtain appropriate approvals where necessary and to ensure that their system is maintained and operated in a safe and sustainable way.

Responsibilities for Permanent Greywater Diversion Devices