Greywater and your property
Greywater forms about two-thirds of the wastewater from a residential household. There is the potential to reuse greywater as a source of irrigating gardens, particularly during periods of low rainfall.
However, greywater can also contain micro-organisms which are harmful to human health, and high levels of salts and other contaminants which can make the soil unusable if it is not properly managed. There is also the potential for contaminating waterways, which can result in algal blooms amongst other impacts.
What is greywater?
Greywater is the wastewater from your shower, bath, hand basin, laundry tub and washing machine. It does not include wastewater from a kitchen, toilet or urinal.
Using untreated wastewater from a dishwasher or kitchen sink is not recommended as it has a higher load of chemicals, fats and organic matter that can clog soils, attract vermin and create unwanted smells.
Greywater is not suitable for drinking, and untreated greywater should not be stored or come into direct contact with humans or animals. However, where greywater is collected safely, it can be used to water your gardens without using mains water, which can save hundreds of litres of fresh water each day.
Reusing greywater provides a number of benefits, including:
- irrigating your garden during dry periods
- allowing you to water your garden when water restrictions prevent you from using mains water
- reducing your water consumption
- reducing your water bills
- reducing the amount of treatment and discharge by municipal sewage treatment plants.
Do I need Council approval to reuse my greywater?
Some types of greywater disposal require Council approval. Please see below, the different types of greywater disposal and whether Council approval is needed.
Types of greywater disposal
- Small quantities of greywater are captured in a bucket for reuse immediately outside on gardens or lawns.
- Council approval is not required.
Greywater diversion devices
- A domestic greywater diversion device may be installed and used without the prior approval of Council under certain conditions, including:
- the property is connected to Council's sewer (ie, does not have an onsite sewage management system such as a septic tank or aerated wastewater treatment system)
- the site is not located in an environmentally sensitive area
- it is on a single domestic dwelling (not multiple dwellings such as units, strata title properties etc,)
- greywater must not be stored or treated other than primary screening or filtering, and must be disposed of by a sub-surface irrigation system at least 100mm below ground
- a 'Water Mark' licensed diversion device is used and installed by a licensed plumber in accordance with the National Plumbing and Drainage Code
- the property and installation meets the exempt provisions of Regulation 75A of the Local Government [General] Regulation 2005.
Domestic greywater treatment systems
- Domestic greywater treatment systems are more advanced than diversion devices - they collect, store, treat and disinfect greywater, which can then be used in washing machines, to flush toilets and irrigate gardens.
- Council approval is required to use the treatment system and it must be fitted by a licensed plumber.
You can apply for approval from Council:
- Plumbing Code standards and notes - NSW Government Fair Trading
- NSW Guidelines for Greywater Reuse in Sewered, Single Household Residential Premises - NSW Department of Planning, Industry and Environment.
We can help you
If you need more information about greywater, please contact our Public and Environmental Health Team:
- T: 02 4474 1310
- E: Council's Public and Environmental Health Team