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Why do septic systems fail?

Septic systems are located on properties and help treat and dispose of wastewater. The types of systems, their capabilities and their size depend on a range of factors, however they are have one common goal - treat wastewater.

Why do septic systems fail?

But what happens if a septic system fails? What do you do and what causes a septic system to fail? These questions, plus many more, are answered below. If you are after further information, give Express Wastewater a call on 1300 722 517 and we would be happy to help.

What is a septic system?

If your property isn't connected to the Municipal sewerage system, the treatment and disposal of wastewater must occur on your property. One of the oldest known treatment and disposal systems is that of the septic system, and it is also one of the most common. Due to the way the system is structured, it must be managed in a way that is not detrimental to the environment, cause a problem for you or your neighbours or create unhealthy condition, and works by breaking down the solid matter from wastewater using millions of microorganisms.

What does it mean when a septic system is failing?

If a septic system is failing, it is neither treating nor disposing of wastewater in the correct way. This can mean that untreated, or incorrectly treated, wastewater is being released onto surface areas, or back through the pipes into your home. And, If a septic system is failing, this can have negative effects on the environment, as well as your health and wellbeing.

In other words, a failing septic system is when the sludge and scum build up to a point where it makes its way up both the inlet pipe and outlet pipe of your tank. This blockage will then cause your home to be backed up and dramatically increase the risk of flooding.

Why does a septic system fail?

There are a range of reasons that can cause a septic system to fail, including:

  • Overloading your septic system with more water than it can handle.
  • Incorrect maintenance, or not enough maintenance (or no maintenance at all).
  • Incorrect installation.
  • Poor design.
  • Incorrect septic system for the property (e.g. too small).
  • Damage to the septic system (e.g. tree roots in piping).
Septic System Damage

In particular:

  • The outlet baffle is clogged.
  • The effluent filter is blocked.
  • There is a blockage in the pipe between the septic tank and your home.
  • The inlet baffle to the septic tank is blocked.
  • The effluent disposal area fails, or becomes over-saturated with water.
Is your septic system failing? Let our septic system experts help you.

What are the signs of septic system failure?

There are a few signs and symptoms to indicate your septic system is failing:

  • A bad smell coming from your septic system.
  • Need for frequent pumping of your septic system (more than once a year).
  • Your toilets, sinks and/or drains keep backing up.
  • Your shower or bath (or even your sinks) are slow to drain.
  • Your household plumbing is making gurgling noises.
  • There are constant wet or damp spots near your septic tank or near the effluent release point.
  • If you have a water well, there are high levels of nutrients (in particular ammonia) and noxious bacteria in the water.

What should you do if your septic system fails?

Despite all the maintenance in the world, sometimes a septic system still fails. If you find that your septic tank has failed, or is failing, try the following:

  • Contact a local wastewater professional as soon as possible and any relevant local health or plumbing authorities.
  • Try and conserve as much water as possible until repairs are completed.
  • If there is sewage on the ground in your yard, fence off the area to stop children and animals from getting to it.
  • Do not redirect your sewage to other locations, as this is illegal.
  • Do not just place soil over any sewage that has made its way to the surface, as this can cause it to backup into your household pipes.

Do not ignore the problem, as it will not just simply 'go away'. The longer you leave it, the worse it can get, so attending to issues promptly can save a lot of time and money.

How can you prevent your septic system from failing?

In order to prevent your septic system from failing, try and complete the following:

  • Complete regular maintenance yourself, as well as organising a professional to systematically complete servicing and/or maintenance.
  • Pump out your system on a regular basis (speak to your local wastewater expert as to how often your septic system should be pumped).
  • Avoid excess water usage whenever possible.
  • Take a look at the specifications of your septic system any time you have a change in your household (e.g. renovations to include additional water fixtures, or another person moves in) to see if the arrangement you have is suitable for your needs.
  • Take great care in what you place down the drain and only use septic system-friendly options.
  • Always replace or repair any leaky fixtures as soon as you find them.
  • Do not drive over the area that houses your septic system.
Express Wastewater

If you would like some assistance with your septic system, or would like to speak to our friendly team regarding installing a septic system on your property, give Express Wastewater a call on 1300 722 517 and we can discuss your wastewater needs today.


Government of Western Australia - Department of Health (Understanding Septic Tank System): https://healthywa.wa.gov.au/Articles/U_Z/Understanding-Septic-Tank-Systems

Office of Local Government - NSW Department of Local Government (The Easy Septic Guide): https://www.olg.nsw.gov.au/sites/default/files/Easy-septic-guide.pdf

City of Gold Coast - Council of the City of the Gold Coast (Care and maintenance of septic systems): https://www.goldcoast.qld.gov.au/planning-and-building/care-maintenance-of-septic-systems-32193.html

City of Ipswich (On-site Wastewater Management): https://www.ipswich.qld.gov.au/__data/assets/pdf_file/0008/109385/af_p0013-A5361174.pdf

Sunshine Coast Council (On-site treatment and greywater): https://www.sunshinecoast.qld.gov.au/Development/Building-and-Plumbing/Onsite-Treatment-and-Greywater