Effluent Disposal

All buildings that produce wastewater are required to connect to either the main sewer or an effluent disposal system.

Building a new home

Property owners building on vacant land are required to connect to water and main sewer services if available.

To find out if your property has availability to water or sewer services, the Water Corporation’s ‘My Water’ online account service provides information on water and sewer availability and water meter location. For more information on getting connected, contact the Water Corporation on 13 13 95.

In areas where main sewer is not available an effluent disposal system needs to be installed.  There are a variety of systems available which range from conventional septic systems (tanks and leach drains), Aerobic Treatment Units (ATU’s) and Greywater re-use systems.

Effluent disposal falls under the Health (Treatment of Sewerage and Disposal of Effluent and Liquid Waste) Regulations 1974. The Department of Health have a list of approved wastewater systems for use in Western Australia (WA).

There are a number of factors to consider when choosing the right type of system for a property and this might include:

  • whether there is adequate space to accommodate the system
  • location and distance of water bodies
  • depth to groundwater
  • any other requirements.

There may also be specific requirements placed on a property indicating the type of system required and its location, which can sometimes be found on your certificate of title or by contacting the City.

Application and approval process

The City's Health Service is responsible for assessing and approving applications for on-site effluent disposal systems.  

An application form must be submitted, ensuring that all required information is provided on a scale plan such as:

  • location of buildings
  • boundaries
  • bores
  • subsoil drains
  • water bodies and preferred location of the system.

Once the application form has been received, the site and system will be assessed for suitability and to ensure that all requirements are met prior to issuing an Approval to Construct. Please note it may sometimes be necessary to request further investigation such as requiring a test hole to be dug to check for groundwater or even a geotechnical report.

Some applications that require Department of Health approval will be forwarded to the Department and will incur a separate fee as stated on the application form.

Once the system has been installed, the installer will need to contact Health Services for a final inspection to be undertaken. If the system has been appropriately installed and complies with the conditions of approval, a Permit to Use will be issued. Please note it is an offence to occupy a house or use a system without a Permit to Use having been issued.

The Department of Health’s Wastewater page provides more information on wastewater management in WA and approved effluent disposal systems.

Effluent disposal systems

Conventional Septic Systems

Conventional systems generally incorporate two septic tanks and two leach drains although there are some systems with a single baffled tank. 

Aerobic Treatment Units (ATUs)

The system incorporates a tank or series of tanks which treats the waste and disposes of the resultant treated effluent via an irrigation field or sometimes, leach drains.

Greywater Re-Use Systems

These systems treat wastewater from bathrooms and laundries to enable it to be re-used to water gardens.

© City of Kalamunda 2019