Septic tank systems
A septic tank system is a type of wastewater management system.
It is usually installed when a property is not connected to sewerage.
It is designed to separate solids, grease and oils from wastewater.
How a septic tank system works
A septic tank system works as follows:
- Wastewater passes through the septic tank.
- Heavier solids sink to the bottom.
- Bacteria breaks down the solids and changes it to sludge.
- The sludge builds up in the bottom of the septic tank.
- Grease and oil float to the surface to form a crust over the liquid (scum).
- The remaining liquid (effluent) flows from the tank into the drainage beds or trenches.
- The liquid soaks into the surrounding soil.
How to look after your septic tank system
If you own a septic tank system, you are responsible for making sure it works properly.
You should also check your septic tank after a flood or cyclone.
Remove, reuse or destroy a system
If you no longer need your septic tank, find out how to remove, reuse or destroy it.
Ballina Shire Council, NSW (2017) fact sheet 2 - How your septic tank works, BSC website, accessed November 2020.
Last updated: 02 December 2020
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