How to tell if my drain field is failing

Are you having problems with your septic system? Then you might be experiencing the effects of drain field failure. Many homeowners leave issues like this unsolved for far too long, and it can lead to sewage backup which floods the building and costs a fortune to repair. So you can detect drain field failure before it reaches a critical stage, here is a list of signs to watch out for.

Water Backup

One of the main signs of drain field failure is when water backs up in your drains. If you have a normal amount of water in your toilet but you still need to flush it multiple times, then it has probably failed.


If a septic odour is hanging around your backyard, or rising from your drains, it is a clear sign you might have drain field failure.The smell is caused by the drain field’s liquid waste collecting in the soil.


One way to find out is by looking in your back garden for damp spots, puddles or even areas which are greener or have a denser growth of grass. If it hasn’t rained and there are still puddles, it might be the drain field. This is because when it fails the liquid waste runs out of space within the septic tank and surfaces.


Gurgling or ‘burping’ sounds coming from your drains is an early sign that the drain isn’t venting properly. You might also hear these noises coming from other plumbing fixtures, even the toilet. This means you have some sort of blockage in your drainage system.

Sludge or slime

A sign of when it becomes a more serious problem is if you find a black slimy substance on the ground above your septic tank; or if there is also a significant layer of sludge or scum inside the tank.

So what causes a drain field to fail?

When the home’s wastewater enters the septic tank it pushes a portion of the tank’s contents into the drain field, and a functional drain field will hold the water until it can be absorbed into the surrounding soil. Drain field failure can be caused by the household using more water than usual, such as when family comes to stay.  When the water sits in the drain lines too long it forms a slimy, bacterial coating on the walls. This stops the wastewater from draining properly. On days when the household is using a lot of water the lines are never able to dry out, so this causes water backup. Another issue that can occur is excessive amounts of grease, soap and solids collecting in the bottom of the septic system. Then when large amounts of water flush through it, the drain field can easily clog.

Some outside factors which can also trigger it are:

  • Not cleaning or pumping the septic tank often enough.
  • The drain field pipes breaking or collapsing.
  • Cars or heavy equipment compacting the soil.
  • Tree roots breaking into the drainfield and piping.

Once you have identified that there is a problem with your drain field, it is time to call an expert. At Express Drainage Solutions our skilled team investigate any drainage issues and provide a professional solution to customers all over the South East. Get in touch to find out more.