On-site sewage management system (OSMS) refer to wastewater systems situated within a property's boundary that treat the wastewater generated from the property and includes the land application area. These systems are required in areas that are not serviced by Council's sewerage infrastructure. OSMS may include septic tanks, aerated wastewater treatment systems (AWTS) and bio-filter systems.

An effective on-site treatment and land application should ensure the:

  • Protection of public health and safety
  • Improved catchment management
  • Protection of surface and ground waters, the land and vegetation

Council's role

In accordance with the Local Government Act, Council maintains a register of On-site Sewage Management Systems installed within Wagga Wagga. Council's Environmental Health Officers (EHOs) perform regulatory functions which include the monitoring, installation and licensing of septic systems. All OSMS systems are subject to inspections to ensure the system complies with relevant legislation and do not pose a risk to the health of the community. Licensing and inspection fees are charged in accordance with Wagga Wagga City Council's Revenue and Pricing Policy of the current financial year.

Find out more about Council's On-Site Sewage Management Plan:

On-site Sewage Management Plan 2014-2018


All installed on-site sewage management systems must be registered with Council, in order to notify Council of an un-registered OSMS please complete and submit the below form:

Existing On-site Sewage Management System Registration Form 143.6 KB Download

Application to install

Approval from Council is required for the installation, construction or alteration of a human waste water treatment device or storage facility and the drains connected to it. If you are installing a new system or altering an existing system please complete the form below and obtain an Approval from Council prior to commencing works.

Application to Install/Alter/Operate an On-Site Sewage Management System or Greywater Treatment System/Diversion Device 274.9 KB Download

Environmental and public health risks

Poorly operated and maintained OSMS systems can pose a high level of risk to public health and has the potential to cause extensive damage to the environment. However, owners of a well maintained and efficient system can benefit from a reduced health risk, a longer life span to the system and increased property values.

Types of on-site sewage management systems

Conventional septic systems

A conventional septic system in a residential situation, commonly consist of a single tank connected to a series of underground trenches. Conventional systems operate by allowing the influent (in-coming effluent) to settle over time; where the solid particals sink and the fats float to the top of the tank. This allows a layer of clearer liquid to form in between which flows on, to the disposal area.

On average a septic tank requires to be pumped out every five years, this varies due to the size, usage and health of the tank along with the type of chemicals that are used in the household. It is good practice to periodically monitor the level in your septic tank, check for any leaks or blockages from the tank and disposal area.

Aerated Wastewater Treatment Systems (AWTS)

Aerated Wastewater Treatment Systems use mechanised aeration and disinfection processes that allow irrigation of effluent on a designated area as safe means of disposal.

The disposal area connected to an AWTS may consist of above ground sprinklers or a sub-surface dripper system. The wastewater can be used to irrigate lawns and shrubs but must not be applied to fruits and vegetables or come in contact with humans or pets. The disposal area must be signed posted appropriately and fenced or barricaded to exclude the entry of children, vehicles, pets and livestock.

Owners of an AWTS must enter into a service contract with a certified Service Agent to ensure the system is maintained appropriately. Owners must ensure Service Agents forward a copy of the service report to Council. These systems are connected to electricity to operate the pumps and alarm system, therefore it is important to check the system regularly and after a power failure.

Educational resources, fact sheets and further information

Educational resources

Conventional On-Site Sewage Management System Brochure 619.3 KB Download

Conventional On-Site Sewage Management Checklist 103.5 KB Download

Aerated Wastewater Treatment System Brochure 466.9 KB Download

Aerated On-Site Sewage Management Checklist 107.0 KB Download

On-site sewage management fact sheets

Fact Sheet 1 - What is an On-site Sewage Management System 548.7 KB Download

Fact Sheet 2 - Roles & Responsibilities Conventional System 533.2 KB Download

Fact Sheet 3 - Roles & Responsibilities Aerated Wastewater Treatment System 458.5 KB Download

Fact Sheet 4 - Design and Construction of Disposal Areas for OSMS 459.1 KB Download

Fact Sheet 5 - Installing or Altering an OSMS 576.1 KB Download

Fact Sheet 6 - Design of Disposal Areas in Accordance to AS 1547 769.6 KB Download

Fact Sheet 7 - Vegetation Suitable for Disposal Irrigation Areas 110.9 KB Download

Request for information

To request a septic licence search please complete and submit a 'Conveyance Certificate' application form available from Council's Customer Service Centre or by clicking here.

Further information