Whitehorse City Council

Greywater & Waste Water Systems

Greywater

Although rainwater is the best way of using non-drinking water for garden irrigation and toilet flushing, greywater systems (all non-toilet and non-kitchen sink wastewater) can also be used in sewered areas for garden irrigation and, depending upon the type of system installed, toilet flushing. Using greywater will reduce the amount of drinking water used and the amount of sewage effluent that has to be treated and disposed of. However, greywater reuse and recycling can pose a risk to public health and the environment.

How Can I Use Greywater?

Greywater can be used to water gardens and lawns. Please note, greywater should not be used on fruit and vegetable plants that will be eaten raw. It can plumbed back into the house to flush the toilet. This must be done by a licensed plumber and permits may be required. Treated greywater can be used for a number of purposes including surface and sub-surface irrigation of lawns and garden beds (excluding the vegetable patch) and toilet flushing. The level of treatment will determine the final use of the greywater. Least treatment for sub-surface irrigation and highest level of treatment for toilet flushing. Further information can be found in Table 5.1 of the Environment Protection Authority Code of Practice – Onsite Wastewater Management.

Untreated greywater from the bath, shower or washing machine can be bucketed or diverted to water lawns and gardens, as a temporary measure during very dry weather. This does not need a permit but to protect your health you should follow the guidelines in the EPA publication Greywater use around the home. Do not store this water for more than 24 hours. For more information visit, the EPA website

Because there is a high risk to public health and the environment, a permit must be obtained from Council. These systems must be installed, operated and maintained in accordance with the Council Permit and the relevant Certificate of Approval for the treatment system installed. These systems must be installed by a licensed plumber.

For more information about applying for a permit to install a system, contact the Environmental Health Unit on 9262 6197.

Should Greywater Be Treated? 

Treating greywater means changing the biological, physical or chemical properties of the water. This can include filtration, storage, aeration or installing a mechanical treating process.

The Environment Protection Authority (EPA) must approve greywater treatment systems that are designed to treat up to 5,000 litres per day before council can issue a permit for installation.

There is no specific legislation banning the use of untreated greywater in Victoria but it is important to understand that untreated grey water may be associated with health risks. The Department of Human Services does not recommend the re-use of untreated grey water inside the home. Untreated grey water must not be stored for more than 24 hours as it has the potential to become septic.  

Is Greywater Safe? 

Grey water contains a large number of bacteria, which could pose a risk to human health, pets and the environment. Treated grey water is safe for some household uses, provided it is collected and used appropriately.  

Tips for Using Greywater

  • Don't spray or hose grey water
  • Use a below ground system to distribute the water to your garden such as a soaker system
  • Alternate watering areas in the garden to avoid the build up of chemicals in one spot
  • Regularly check that your irrigation pipes are not blocked. You may need a screen or filter to stop lint, hair and grease from clogging your pipes
  • Untreated kitchen water should not be used because it can contain grease and detergents
  • Take care when choosing detergents and other household cleaning products. Some shampoos, laundry detergents and cleaning products could cause damage to the garden as they may contain harmful chemicals like chlorine, sodium and phosphorous
  • Check the labels carefully 
  • Water used to wash soiled nappies should be avoided at all costs
  • Rinse water from the washing machine is the 'best quality' grey water 

Council Regulations

Keep greywater within the boundaries of your property and make sure that it doesn't enter the stormwater drains.

There is no specific legislation banning the use of untreated greywater in Victoria but it is important to understand that untreated greywater may pose risks to health. Untreated greywater must not be stored for more than 24 hours as it has the potential to become septic. Greywater stored for more than 24 hours will require a permit from Council: pdf icon Septic tank application to install.doc (93.76kB)

Council officers may investigate greywater that places public health at risk under the nuisance provisions of the Health Act 1958. The EPA may investigate grey water that causes environmental pollution under the Environment Protection Act 1970.

Please check with Council before installing a grey water system (see details below).  

Who Can I Ask About Greywater?

  • Your licensed plumber
  • Council's Sustainability Unit on 9262 6363
  • Council's Environmental Health Unit on 9262 6445
  • Environment Protection Authority on 9695 2722

Waste Water

Despite being in a predominately sewered area there are still over 40 septic systems within the municipality.

Owners of properties that have a septic system are required to maintain their system in good working order so that all wastewater is treated and contained onsite.

To ensure that your septic system remains in good condition follow these simple steps:

  • Minimise the amount of strong detergent and disinfectant flushed down the system (look for cleaning chemicals that are “septic safe”).
  • Minimise the amount of fats and oils washed into the system.
  • Do not build or construct driveways, tennis courts, out buildings or otherwise seal over the drainage area.
  • Be careful what you flush down the system, septic systems are more prone to blockages than sewered properties.
  • If you have a septic tank, pump it out every 3 – 5 years so that the drainage field does not become clogged.
  • If you have a treatment plant, ensure that it is serviced regularly, in line with the conditions on your Permit to Use and the system’s Certificate of Approval, issued by the Environment Protection Authority. 

You should contact a licensed plumber if you believe that your septic system is starting to fail.

If you have an existing septic system and wish to make an alteration or extension to the system, please complete and submit the following form: pdf icon Septic tank application to install (93.76kB). All works must be carried out by a licensed plumber. The plumber may make the application on your behalf.

For More Information