On-site sewerage facilities

On-site sewerage facilities (OSSF) consist of wastewater treatment plants and effluent disposal areas that treat and dispose the sewerage generated from the property within property boundaries. OSSF include all types of wastewater treatment and land application, such as:

  • septic tanks
  • aerated wastewater treatment systems
  • passive wastewater treatment systems
  • composting toilets.

These systems are required in areas not serviced by Council sewerage infrastructure.

Well-maintained facilities protect public health and safety as well as reduce the risk of widespread environmental harm.

We regulate:

  • new OSSF installations
  • alterations and additions to existing systems
  • effluent run-off complaints
  • licensed service persons
  • site and soil evaluators
  • auditing and monitoring.

Download On-site sewerage facilities management system – List of authorised service agents(PDF, 311KB)


There are different kinds of approvals needed for installation, maintenance and compliance of on-site sewerage facilities. Select from the following applications.

Renovation and extension work

When carrying out building work to add one or more bedrooms to a house in a non-sewered area, you will need to apply for a concurrency certificate. To apply for a certificate, you must submit a concurrency report that shows the existing on-site sewerage facility can cope with the additional load created by the extra bedroom(s).

For more information, visit our Concurrency plumbing and drainage page.


On-site sewerage facilities must comply with: