Onsite Wastewater Management System maintenance

Good management of your onsite wastewater system and disposal area 

As the owner or occupier of a dwelling with an onsite wastewater management system, it is your responsibility to make sure it is well maintained and works effectively. A well-maintained system will safeguard your family's health, protect the environment and neighbouring properties.

New Environment Protection Regulations 2021 commenced on 1 July 2021.

Part 5.7 of these regulations require owners and occupiers of onsite wastewater systems to:

  • maintain the system in good working order
  • ensure those operating the system have the information they need to operate and maintain it effectively
  • respond to any system failures.

These obligations under the Regulations apply to all systems, including older systems that didn’t have a permit when they were installed.

If a system is well maintained, you will:

  • minimise health risks to your family and the broader community
  • protect ground and surface waters
  • prevent the degradation of land and vegetation systems
  • protect activities such as swimming and tourism that are dependent on waterways.

Please contact Maroondah City Council for further information on maintaining your septic system.

How to achieve the most from your system


  • Learn the location and layout of your septic system and disposal area.
  • If you have a treatment system, have it inspected and serviced quarterly by a wastewater servicing contractor and provide Council with a copy of the servicing report.
  • Regularly maintain the disposal/irrigation area by keeping grass short and reducing weeds.
  • Have your septic tank de-sludged (pumped out) every 3 – 5 years to prevent sludge build up and prevent problems.
  • Prevent the entry of stormwater onto the disposal/irrigation area and into your septic tank.
  • Ensure your tank is well sealed.
  • Conserve water by using water efficient devices in your home.
  • Check household products for suitability for use with a septic tank.
  • Have your grease trap (if installed) cleaned out regularly.
  • Keep a record of de-sludging and maintenance. 


  • Allow livestock to graze or drive a vehicle on the disposal area.
  • Discharge wastewater into waterways, dams or drains.
  • Put large quantities of bleach and disinfectants down the drain.
  • Allow any foreign materials such as nappies and sanitary napkins to enter the system.
  • Put fats, oils or food waste down the drain.
  • Install or use a garbage grinder or spa bath if your system is not designed for it.
  • Pour medicines/antibiotics down the drain. They can kill the essential bacteria in your septic system.

How do I know if there is a problem? 

Indications of a problem with your septic system include:

  • foul smells from the tank or disposal area
  • toilets and drains that back up or drain slowly
  • excessive noise from the pump or blower (treatment systems)
  • high water level in the septic tank
  • tanks not de-sludged in the last three years
  • a wet/soggy disposal area.

Do not ignore the problem. A poor performing septic system will impact on the environment and public health. It could also cost you significantly in the long term. 

For operational problems with an existing system you should contact a licensed plumber.

Connecting to sewer?

If your property is connecting to reticulated sewer or you are replacing an old system, the septic tanks must be decommissioned.  All works are to be carried out by a licensed plumber in accordance with EPA guidelines. The plumber will ensure the tanks are properly cleaned, disinfected and filled and pipes are permanently sealed. You will be required to submit a copy of the decommissioning certificate to Council.

When will sewer become available to my area?

Yarra Valley Water have developed a Community Sewerage Program to prioritise areas that will become sewered. For information about your area in the Community Sewerage program, please contact Yarra Valley Water on 1300 853 811.

Further information

Contact Council’s Community Health team on 9294 5603:

  • for advice on domestic wastewater system maintenance
  • before carrying out any alterations or modifications to existing systems
  • before installing a new system.

For further information on the new Environment Protection Regulations 2021 and the Environment Protection Act 2017, including the General Environmental Duty (GED),  please visit EPA’s website.