Onsite wastewater management systems (including septic tank systems) are used on residential, community and business premises in unsewered areas. They treat, recycle or dispose of sewage. Sewage is combined wastewater from bathrooms, kitchens and toilets etc. 

Read more about treating wastewater.

If you are an owner or occupier (such as a renter) of land with an onsite wastewater management system, there are laws that apply to you. 

The Environment Protection Act 2017 (the Act) and Environment Protection Regulations 2021 (the Regulations) include requirements for installing a system properly and operating and maintaining it. 

Permit for constructing, installing or altering a system not exceeding 5000L per day

If you want to construct or install, or alter an existing an onsite wastewater management system, you must apply for a permit from your local council. 

Council permits are required for smaller-scale systems with a design or actual flow rate of sewage not more than 5000L on any day. This is an A20 permit activity under the Regulations. Council can refuse a permit if the proposed onsite wastewater management system doesn’t meet the Act’s requirements. 

Systems that can treat more than 5000L per day need an EPA development licence and operating licence  (unless an exemption  applies).

Refer to the following resources for more information:

• Standards  for onsite wastewater treatment plants set by EPA
• List of some treatment plants that hold Australian Standard  certificates
• Permit exemptions for onsite wastewater management systems.

Operating and maintaining an onsite wastewater management system 

If you are an owner or occupier of land with an onsite wastewater management system, you have legal obligations.  The Regulations include requirements for both landowners and occupiers, including renters. Others only apply to landowners. This includes:

• operating the system correctly 
• making sure it does not overflow 
• maintaining the system in good working order (this doesn’t apply to renters)
• notifying the local council as soon as is practical if there is a problem with the system.

Landowners must also: 

• provide written information about how to use the system to the person in management or control of the system (for example a renter)
• keep maintenance records (and provide them to council when requested).

These requirements apply to all systems, including older systems.

Councils have powers to enforce these requirements. They can order system maintenance and take enforcement action, such as issuing a fine, for breaches of duties. 

Read more about how to manage your own onsite wastewater system.

• Keep your wastewater or septic system in good working order
• Don’t overload the system
• Manage the risk when disposing the treated sewage to the land.

• Code of practice – Onsite wastewater management (publication 891)
• Guidance for owners and occupiers of land with onsite wastewater management system ≤ 5000 litres on any day (including septic tank systems) (publication 1976)