Apply to install or alter a septic system | City of Casey
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Apply to install or alter a septic system

Choose the right septic system for your property

You should choose a septic system suitable for your property and surrounding area. Find out more on the different types of septic systems available.

You should have a qualified consultant asses your property before you apply to install or alter your septic system.

To find out how you can have your property assessed and which system is most suitable to you:

Things you will need before you apply

Soil percolation test

You need to conduct a soil percolation test before you apply for a permit to install a septic system.

Provide a site plan

You must provide a site plan with your application form. Your site plan must show:

  • The proposed dwelling and ancillary buildings/structures
  • Septic tank location
  • Disposal area
  • Nearby waterbodies and retarding basins

Provide a floor plan

You must also provide a floor plan of the dwelling including existing floor plan/new floor plan for dwelling additions.


  • Install a new septic system: $635
  • Alter an existing septic system: $635
  • Minor alterations to an existing system: $225

How to apply

To apply for a permit to install or alter a septic system, you or your plumber must complete and provide:

​​​​​For more information on the application process, please read our Applying to Install or Alter a Septic System document.

Submit the documents and payment:

What happens next?

  • Once we have received the required documentation (soil percolation test, site plan, floor plan and application to install or alter your septic system) and the fee has been paid, we will contact you within 5 business days to issue your permit.
  • We may require further information, or need you to alter your plans, in this case we will contact you within 5 business days.

Before you can use your septic system

Before you can use your system:

  • You must provide us with a certificate of compliance and 'as-laid' plan from your plumber that ensures all works comply with relevant standards and regulations.
  • We will conduct a final inspection of the installation to make sure it meets the criteria of the permit.
  • If your system passes the inspection, we will issue a permit to use the system. You can then begin to use your septic system.
  • You should make sure you maintain your system to avoid having the system fail and be in non-compliance with your permit conditions.