Waste Water

Where deep sewer is not available to a property, an onsite wastewater disposal system must be installed.   Several different systems are approved for use in WA.  For more information on the different types of systems please refer to the Department of Health WA website

Several factors must be considered when choosing the right system and location for your property.   The main factors include the available space on the property to accommodate the system and the local soil conditions, including the depth to groundwater. 

Refer to the Guidelines for the Installation of an Apparatus for the Treatment of Sewage information sheet for more detailed information.  An onsite wastewater application form can be downloaded here.

Application and Approval

Prior to installing a new or altering an existing onsite wastewater system and application must be lodged with the Shire of Plantagenet Environmental Health Officer. Click on this link to download the ‘Application to Construct or Install an Apparatus for the Treatment of Sewage’ form.  

Once an application has been received, the site and system will be assessed for suitability and if all requirements are satisfied, an ‘Approval to Construct’ will be issued. 

Once the system has been installed, and prior to the system being covered with soil, the installer will need to contact the Shire of Plantagenet Environmental Health Officer to arrange for a final inspection to ensure the system has been installed as per the approval.  Within 7 days of the final inspection taking place, an ‘as-constructed’ plumbers plan must be submitted to the Shire of Plantagenet.  Once the final installation of the system has been approved, then a ‘Permit to Use’ will be issued to the property owner.  Please note that it is an offence to occupy a house or use a system without a ‘Permit to Use’ having been issued.

Maintaining a system

To ensure optimum operation of a septic system, a few basic maintenance items must be regularly attended to.

  • Alternate the leach drains by switching the diverter device on a regular basis. It is recommended that each leach drain is rested every 6 – 12 months.
  • Ensure septic tanks are pumped out on a regular basis. The actual timing will depend on the usage, but on average for a two-bedroom house it is recommended that the tanks be pumped out every 8 - 9 years.  Please be advised that only licensed liquid waste contractors can pump out septic tanks. 
  • Ensure any alternative treatment system is regularly serviced by a qualified agent as per the approved maintenance agreement and that the agent submits the service reports to the Shire of Plantagenet on a regular basis.