Septic Tank Decommissioning


As part of the State Government's Infill Sewer Program, many properties in City Beach previously serviced by septic tank and effluent disposal systems can now connect to a sewer.

When does a septic tank need to be decommissioned?

There is no legal obligation to have an unused septic tank system decommissioned at the time of sewer connection, unless:

  • The property is sold, in which case the septic system is to be decommissioned within 60 days of settlement of the property.
  • Building extensions encroach on minimum clearances from the system. Septic tanks must be located at least 1.2 metres from any building or boundary and leach drains/soakwells must be located 1.8 metres from any building or boundary.
  • If the permitted use of the development changes e.g. from a residence to a commercial use.

Although the regulations don't make it mandatory to do so, decommissioning should be considered as leaving a redundant septic tank and effluent disposal system on your property will lead to the tanks eventually collapsing. Decommissioning would also minimise potential personal liability.

Decommission process

The following decommissioning process should be followed:

  • Ensure all old septic tanks, soak wells and/or leach drains are pumped out by a Licensed Liquid Waste Contractor
  • Either totally remove the system or if impractical, remove the lids and break the bases of the tanks - please do not replace lids
  • Once the cavity or the broken tanks have been filled with clean sand and compacted, forward the receipt and photographs of the work to prove that decommissioning has been completed
  • Email or post the receipt and photographs to the Town's Health Services.

The Town's Health Services will issue a Certificate of Decommissioning. The certificate confirms that the old septic system has been properly decommissioned and is a useful document particularly if/when the property is sold or developed at any time in the future. Until confirmation of decommissioning is provided to the Town, the Town's database will reflect the existence of an effluent disposal system. For further information, please contact the Town's Health Services on (08) 9347 6000.

Demolition permits

demolition permit is required for the demolition, dismantling or removal of a building or incidental structure from properties in the Town of Cambridge.

Applying for a demolition permit

To ensure you provide us with all the documents, fees and information required to process your application please complete a Demolition Permit Checklist

Asbestos and Septic Tank Declaration

Complete the below forms as part of your Demolition Permit application.

Complete an Asbestos Declaration

Complete a Septic Tank Declaration

Complete a Certification of Decommissioning of an Effluent Disposal System Form(PDF, 117KB)