Wastewater Systems (Septics)

Wastewater Systems (Septics)
Wastewater systems

Wastewater systems

Onsite disposal of wastewater is required in areas where reticulated sewerage is unavailable.

Every onsite wastewater system requires an approval. 

For further information regarding wastewater systems, visit the Dept of Health Website.

Department of Heath Wastewater systems

Septic Tanks

Septic Tanks

All wastewater system (including septic tanks) installations must be applied for and assessed by the Shire of Irwin’s Environmental Health Officer (EHO) before any works can commence.  

  • systems to be installed must have approval for use in Western Australia by the Department of Health
  • construction of the apparatus shall be in accordance with the requirements of the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974
  • approval will not be given for the installation of an apparatus where a sewer connection is available as provided for by the Heath Act 1911.
How do I lodge my application?

All applications are to be submitted to the Shire of Irwin:

  • Approval will be given either by the Shire of Irwin or the Department of Health (depending on system requirements)
  • Form - Application to Construct or Install an Apparatus for the Treatment of Sewage 
  • Fee - payable upon application

Include with each application: 

  • 2 sets of site plans for Shire approval 
  • 3 sets of site plans for Department of Health approval

Site Plans are to include the following:

  • Scale of drawing, either 1:100, 1:200 or 1:500
  • Location of effluent disposal system and all drains and pipework
  • Indicate the size of the tanks
  • Distance of the system from all buildings, boundaries, bores, waterway and waterbodies
  • Distance of system from all trafficable areas
  • Site plan to have contour lines indicating the slope of the land

Note: Any change from what has been approved must be reviewed by the Shire before installation, which may require the submission of amended plans.

Approval Process

Approval to Construct or Install

Once your application is approved you will receive an APPROVAL TO CONSTRUCT OR INSTALL AN APPARATUS FOR THE TREATMENT OF SEWAGE.  

An approval must be issued to you before you commence work on installing septics.


Once the system is installed it is required to be inspected  by the EHO before the system is covered.  Please contact the Regulatory Services Department for inspection details. 

A Compliance Certificate from the Plumber also required by the Shire at this stage.

Permit to Use

Once your system has been inspected and has been installed correctly, you will then receive a PERMIT TO USE.  The system is then considered ready to use.  

Note: It is an offence to use a system without a permit to use.

Decommissioning Septic Tanks

When a developed property is connected to sewer, any onsite effluent disposal systems such as septic tank and leach drain/soakwell systems will  require decommissioning.

Under the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974 decommissioning is required when:

  • The property is sold
  • The use of the development changes e.g. from a residence to a child care centre
  • Building extensions may encroach on minimum setback requirements for the system

Septic tanks which have not been decommissioned must not be paved or built over without approval from the Shire.  

Please notify the Shire when a system has been decommissioned by forwarding a letter to the Shire with a copy of the certification from the liquid waste contractor.

For further information on requirements around decommissioning septic tanks, visit the Department of Health

Application form & fees

The application form and fees are set by the Department of Health

Applicaton form



Govt Dept.Fee TypeFee
Local Government

Application Fee (fee is also applicable if a report is required for Dept of Health)


Dept of HealthApplication Fee - with a local government report$66
Dept of HealthApplication fee - without a local governmen report*$110
Local Government

Permit to Use fee (includes all inspections and if approval to construct is granted by Dept of Health*)


* only permitted when the local government fails to provide a local government report within 28 days of request

See the application form for details on how to pay the Department of Health fee

Contact Information

Contact Info

For waste water enquiries, please contact Regulatory Services Environmental Health Officer on  9927 0000