choosing a greywater unit factsheet

A grey-water system is a great way to collect and re-use domestic wastewater from your bath, laundry or shower in order to reduce your overall water usage and recycle what you do use!

When deciding on installing a greywater unit, there are a number of factors to consider:

  • What garden zones you have that could use greywater
  • What greywater your home produces
  • The type of unit – whether temporary or permanent

Can you use greywater in your garden?

The end-use of your greywater system largely depends on the quality of treatment, however as a general guide greywater is best suited to fruit trees, where fruit is well above the ground; nutrient and water loving exotic plants that can handle alkaline water; and areas of lawn. You should avoid the use of greywater in areas where it will make direct contact with low lying fruit, vegetables and herbs that you eat. Greywater can also be recycled through your household toilets.

Sources of grey-water in your home

Greywater can come from your washing machine, shower, bath, most bathroom hand basins and potentially the kitchen sink if you don’t use a lot of cleaning products and detergents which are high in sodium and phosphorous. Greywater does not include wastewater from toilets which is classified as blackwater.


Greywater can be classified into two categories – treated and untreated – and greywater can be temporarily or permanently diverted for use. An example of a temporary diversion is plastic pipes connected from the laundry to the garden. Whilst a permanent diversion is plumbed directly into the plumbing or drainage system of your home, some greywater systems even allow you to add your own liquid fertilisers as needed through the greywater reticulation to the plant roots. A temporary diversion can be an inexpensive option to start utilising your grey-water straight away.

Quick steps to installing a Greywater Unit
1. Consider your greywater sources and where it can be used in your garden.
2. Get advice from suppliers on WA Department of Health approved systems and decide on the type of system suitable for you.
3. Get quotes. Prices can range considerably; $500 for a simple gravity fed system to several thousands of dollars for a pumped system.
4. Contact your Council’s Environmental Health Officer for an application form.
5. Submit the form with drawings to your Council. Note, this may also require a processing fee.
6. If approved, install the system with the assistance of a licensed plumber connecting the system to house wastewater pipes.
7. Contact your council to check your system is safe and get your ‘permit to use apparatus’.