A large number of properties across the region are not connected to a reticulated sewerage system. The treatment and disposal of all wastewater generated on these properties must be undertaken by an on-site sewerage facility.


On-site sewerage facility (OSSF)

An on-site sewerage facility is any system that stores, treats and disposes of household wastewater on the property. Not regularly maintaining or positioning an OSSF in the wrong spot can impact public health and the environment. The owner of the facility is responsible for ensuring the system is maintained and functioning properly.

Prior to installing an on-site sewage facility approval must be obtained.

The types of facilities that may be installed are:

  • septic tank
  • secondary or higher treatment plant (aerobic wastewater treatment systems)
  • composting toilet.

A list of the approved treatment systems is available from the Queensland Government website.

Larger onsite systems with over 20 equivalent persons require ERA 63 approval and further monitoring from the Department of Environment and Heritage Protection

The site and soil evaluator

One of the important aspects when installing an OSSF is the requirement for a thorough site and soil evaluation to be undertaken as part of the process of obtaining approval for effluent disposal within the property. It is essential for the evaluator to select the most suitable on-site effluent disposal facility for the property and engage the best environmental practices to support property design. The quality of effluent from an on-site sewerage facility is a key consideration to determine how sewage effluent is to be controlled and disposed of within the property.

Before lodging an application to install an on-site sewerage facility, it is recommended that the property owner consults with a site and soil evaluator to discuss the options available for effluent disposal within the property.


Maintenance arrangements

Maintenance is essential for the satisfactory performance of these facilities.

Septic tanks

We recommend that septic tanks are pumped out every 3-5 years to ensure they continue to operate effectively. A local contractor can be found by searching for “Septic tank pump-out” via the internet.

Secondary or higher treatment plants

Licensed service agents should be engaged to service and monitor the performance of the plant. To understand what is involved in maintaining the plant, contact the manufacturer or a licensed service agent. A local service agent can be found by searching for “wastewater service agent” via the internet.

Council will contact property owners and service agents if a service report has not been received within the usual service intervals.

Penalties apply for failure to maintain an on-site sewage facility.


Additional information

Aerated wastewater treatment system inspection requirements

A permit to install an aerated wastewater treatment system shall only be granted on the condition that the householder has the installation inspected as per the model approval requirements by a servicing agent. A report shall be prepared after each inspection with a copy to be retained by the householder and another to be forwarded to the Council.

The servicing agent must be engaged to carry out any necessary repair work to the installation as well as the routine cleaning and maintenance activities.
Any installation faults revealed in an inspection must be repaired promptly.

Development assessment requirements

We undertake assessment for on-site sewerage facilities under the requirement of the Plumbing and Drainage Act 2002, the Queensland Plumbing and Wastewater Code and our development permit conditions.
The Queensland Plumbing and Wastewater Code sets out the technical requirements for sustainable management, site and soil evaluation, design, installation and operation for on-site sewerage facilities.

This code is to be read in conjunction with AS/NZS 1547 2000, which includes information relating to on-site domestic wastewater management.