Greywater

What is a greywater system?

Greywater is wastewater from a range of sources including your bath, bathroom basin, laundry and shower. It doesn not include blackwater such as wastewater from toilets.

A greywater system enables you to re-use greywater from your home. The average Australian household can re-use around 1,500 litres of greywater each week.

There are simple and complex systems, but they all involve reusing water that would otherwise be lost. Some systems involve storing the water and treating it to remove impurities.

You may be eligible for rebates or assistance to help with the cost of installing a greywater system.

Types of greywater systems

There are three ways that greywater can be used:

• Manual bucketing - collect water from your shower or washing machine in a bucket and use it on the garden. You won’t need council permission to do this.
• Diversion and filtration devices - divert greywater to your garden or lawn using a system that typically has a filter and a pump. This is suitable for sub-surface irrigation only. Check with your local council for licensed devices and approvals.
• Treatment and re-use systems - treat water to a standard fit for household use. This water can be used for toilet flushing, washing clothes and above-ground irrigation. Requires local council approval.

Using greywater outside

The easiest place to start using greywater is on your garden.

Watering with greywater can significantly reduce your overall water use and may help you save on your water bills. It also means you can water your garden during water restrictions.

Greywater for your garden doesn't usually need to be treated but it’s best to use soaps and detergents that are safe to re-use on your garden. Check the label of products before you buy them if you're not sure.

You can bucket water from your bath or run a hose from your washing machine straight onto your garden. You can also catch water in a bucket after rinsing vegetables or while waiting for hot water to come through the tap. This water can go straight onto your garden.

Avoid using greywater on your vegetable garden or herbs, especially if you eat them raw.

If you're using untreated greywater on the garden, talk to your local gardening centre or garden advisor to make sure your soil and plants can handle it. You'll also need to use detergents and powders that are free from or low in phosphate or salt.

Using greywater indoors

Treated greywater can be used indoors in your laundry and toilet.

Toilets and washing machines are two of the biggest water consumers, so using greywater in these appliances can save a lot of water. You will require a high level filtration system and secondary treatment with disinfection to use your greywater indoors.

Treating greywater

Treated greywater can be used more widely in the home and garden than untreated greywater.

Treatment systems may be biological, chemical or mechanical. See Your Home Technical Manual - Wastewater re-use for information on the different types of treatment.

Before you set up a greywater system, make sure that you have met all your local council requirements for greywater re-use. You should also make sure that everyone who visits your home knows how to use the stored greywater safely.

Collecting, storing and using untreated and poorly managed greywater can be hazardous to people and plants. Check the health requirements with your local council or state or territory health authority.

Do's and don'ts of greywater use

Do:

• Wash your hands after watering with greywater
• Use garden-friendly cleaning products that are biodegradable and are free from or low in sodium and phosphorous
• Pipe greywater underground or under mulch to water your garden
• Irrigate your ornamentals and orchards, making sure greywater is not in direct contact with fruit
• Regularly check your greywater system is working properly
• Divert greywater to the sewer during wet periods
• Stop using greywater if someone in the household is sick
• Check your state and local regulations
• Use a licensed plumber to install your system
• Avoid clogged soil by use a coarse filter to reduce the amount of solids in your greywater
• Make sure you contain greywater within your property
  

Don’t

• Store untreated greywater for more than 24 hours
• Use greywater to water vegetables and herbs that are to be eaten raw or partly cooked
• Use greywater sourced from washing nappies or soiled clothes
• Use greywater that has disinfectants and bleaches in it
  
• Use greywater from kitchens, unless it has been treated
• Use greywater that is still hot as it will kill beneficial organisms in the soil
• Spray or hose greywater
• Allow pets to drink greywater.