Septic tank & wastewater treatment

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In Indigo Shire, there are townships and many rural areas that are not connected to North East Water's reticulated network of sewerage infrastructure. As a result, it is estimated that there are 1,700 domestic wastewater management systems across the area, predominately septic tank and absorption trench and aerated wastewater treatment systems. There is also potential for many more such systems to be installed based on existing stocks of unoccupied un-sewered landholdings and future sub-division potential.

Aerated wastewater treatment systems are common within the Shire because areas where a land capability assessment has identified the land is unsuitable for a conventional system requires an alternate system capable of treating effluent to a standard of 20/30 BOD.

Installations and Alterations

For any new installations, an application shall be made on the prescribed form, accompanied by information required to be submitted for a septic tank permit and associated fees. 

Fees for 2017-2018 are:   New Installation $520.00.  Alteration to existing system $257.40  Re-inspection Fees $220.  There is no GST applicable on Septic Permits.

Existing installations are subject to the same requirements as for new system installations where an owner chooses to alter or construct a system or where an alteration or modification is required due to inspections carried out by the Council, proposed alterations to the site or unsatisfactory performance of the system.

Existing domestic wastewater management systems vary in age, design, installation, user hydraulic loading and operation. Varying levels of knowledge amongst owners/occupiers of premises with WMS and system construction and maintenance standards, have an immediate effect on the performance of these systems.


Common issues identified with a variety of on-site systems include:

  • A consistent and offensive wastewater/effluent odour, indicating a potential problem with the absorption trench or primary septic tank in need of a de-sludge waste removal.
  • Cracked lids/open inspection holes, which encourages vermin and is a safety issue.
  • Some residents being unaware that their property is unsewered. Generally this is a problem with properties that are newly tenanted or owners who have recently purchased the property.
  • Decoration and ornamental objects such as ponds, plant containers, or garden features or backfilled material being placed adjacent or on top of systems, restricting access to wastewater management systems and potentially effluent application areas.
  • Owners of Aerated Wastewater Treatment Systems may be under the assumption that final liquid product after treatment is of drinking water quality, therefore are using it in inappropriate places or for inappropriate uses.
  • Effluent distribution lines for Aerated Wastewater Treatment Systems must be purple for drip feed irrigation or black for sub-surface irrigation. Many owners/operators have attached traditional green garden hoses. This is not an approved piece of equipment for effluent distribution as it has the capacity to be connected to the domestic water supply system and can be mistakenly be used for the purposes of potable water supply. This is dangerous, as cross contamination occurs or unfamiliar persons may mistake the effluent being discharged as potable water (tap water).




Last updated: 22 January 2018