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Wastewater Permit Applications - Decommissioning a Septic Tank or Treatment Plant


If your septic tank or treatment plant is no longer needed (e.g. you have connected to sewer or installed a new wastewater system) then the old tank/s need to be made safe.

What do I need to submit?

All works are to be completed by a licensed plumber/ drainer and a notification of decommissioning of a Septic Tank System is to be submitted to Council.

Additional Information

The required decommissioning process is:

  • Tank to be pumped out, rinsed, and rinse water pumped out again by a licensed contractor,
  • Tank bottom to be broken in to release any water that may enter the tank,
  • Top of tank and walls collapsed to below ground level,
  • Tank to be completely filled with clean earth or sand to surrounding ground level.

In some situations tanks may be:

  • Left in place and converted (Pumped out, cleaned, disinfected) for stormwater storage for garden use
  • Treatment plants may be able to be converted for greywater re-use subject to local water authority policy and Permit to Alter a wastewater System issued by Council.
  • Some treatment plant systems may be suitable for extraction and on-selling subject to manufacturer’s approval and re-installation by accredited installer. Contact your treatment plant agent for further advice.

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