The following information is for people who want to reuse greywater from their home. If you grow food commercially, you should read about using recycled water to grow crops.
Greywater is wastewater from bathrooms, laundries and kitchens. You can use greywater to water your lawns and gardens.
You can apply greywater to your garden - using a bucket, container, or temporary hose - or install a permanent greywater system.
Greywater can carry disease, chemicals and dirt. You can reduce the risk by using greywater sensibly.
You can use a bucket, container or temporary hose to apply greywater from your bathroom or laundry to garden or lawn areas.
You must not apply greywater within 50m of a bore that will be used by people to drink or wash.
The chemicals in greywater can damage your house.
The point where you release greywater must be more than:
- 0.5m from a fence, path, driveway or carport
- 1.2m from a boundary without a fence
- 1.2m from buildings other than a carport.
Follow these guidelines for using greywater sensibly:
- don't use greywater if other people in the house are sick
- don't use greywater from washing clothes covered in vomit or faeces - this includes nappies
- don't keep untreated greywater for more than 24 hours
- don't use kitchen wastewater - it must be treated before use
- try not to splash greywater
- keep children away from areas where greywater is used until it has soaked into the ground
- don't let greywater form puddles or run off onto other properties, watercourses and drains
- don't keep watering in one spot - salts and other contaminants will build up
- rotate greywater use with mains and rain water - this will help flush salts from the soil
- don't overwater your plants
- be careful when watering acid-loving plants such as azaleas and camellias - greywater tends to be slightly alkaline
- if plants are damaged, reduce the amount of water used or try a bigger irrigation area
- wash your hands before eating, drinking or smoking.
Permanent greywater systems
The most commonly used permanent greywater systems are diversion devices and treatment systems.
If you want to install a permanent greywater system, you must choose a product that has been approved by the Department of Health. Read about and get lists of approved products.
Laws and regulations to be followed will vary if the device is to be installed either:
Diversion devices use gravity or a pump to move greywater without storing or treating it. No permit or approval is required. These devices must be installed by a licensed plumber.
Gravity diversion devices have a valve, switch or tap fitted to the outlet of a plumbing fixture, such as a laundry sink, to divert greywater for use.
Pump diversion devices use a surge tank to move greywater without storing or treating it. All greywater should be screened as it enters the tank. The screens must be cleaned regularly.
Diversion devices must meet the following criteria:
- each system installed is for a single home only
- you must not store greywater
- you must not use kitchen wastewater
- greywater must not be used for spray irrigation - the system must release it below the surface of the ground
- you must connect an overflow to a sewer or septic tank.
Greywater treatment systems collect, store, treat and may disinfect greywater.
You must use an approved system. It must be installed by a licensed plumber.
If the system is to be installed inside a building control area, the design and installation must also be certified.
The manufacturer or agent for the approved system must fill out a notification of installation of an on-site wastewater system.
When work is finished, they must submit the second part of the form, the notification of installation completion.
The forms must be submitted to the Department of Health using the contact details provided.