On-site wastewater management systems

An on-site wastewater management system receives and / or treats wastewater and sewerage and then disposes this into an approved disposal system or a re-use system. This page has information on:

  • Septic tanks
  • Aerated wastewater treatment systems
  • Waterless composting toilets
  • Hybrid systems

New systems – all building classifications

You need a plumbing permit for any design and connection of on-site water management systems as well as septic tanks.

Certificates of accreditation

You can fill in an Application form for approval of an on-site waste water management system (manufacturers only) and download a copy of a Certificate of current approved systems.

You can get also get a copy of a certificate of a current approved system.

Septic tanks

A septic tank is a watertight chamber filled with household waste water and made of concrete, fibreglass or plastic. Septic tank systems are a type of onsite sewage facility. They are in areas that are not connected to a sewerage system, such as rural areas.


You must have a controlled waste transport business to pump out a septic tank, grease trap, trade waste or do similar maintenance.

An owner, a competent person contracted by the owner or a licensed plumber can provide access for desludging.

Aerated wastewater treatment systems

An aerated waste water treatment system takes normal household waste from toilets, basins, showers, baths and kitchen sinks.  AWTS treat the waste and then distribute treated waste water on site to the land application area.

Note:  The land application area is an important part of the on-site sewerage system.  It distributes the treated wastewater produced within the property.  This water must remain within the property boundary.

It is important to understand that it is not OK to eat anything that has grown from gardens that use treated water. Avoid treated waste water to bare skin contact and contact by pets and livestock.

Buying, putting in and maintaining a AWTS can mean a big up-front and ongoing maintenance cost. We recommend that you choose a system and maintenance contractor that suits your needs.


You need a maintenance contract with a licensed plumber and to let the Permit Authority know when work is completed for servicing of AWTS and any maintenance of like-for-like on an AWTS.

You need a licensed plumber and plumbing permit to replace a failed on-site waste water management system or new waste water land application area.

Technical information

Waterless composting toilets

A waterless composting toilet system breaks down sewerage into a safe recycled product. These systems use little to no water and are a replacement to a flush toilet used with septic systems or sewer systems. They are often used where no suitable water supply or sewage treatment plant is available.

They are found more often in national parks, remote holiday cottages and off-grid homes in Australia.


You need a licensed plumber and plumbing permit to replace a failed composting toilet system or new waste water land application area.

Hybrid systems

A hybrid waste water system is an alternative to sewerage, septic tanks and pump-out systems.  Most hybrid systems market as an environmental solution for processing sewerage.

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Updated: 09 Jun 2020