How to tell if your septic tank needs emptying

Updated June 18, 2018

The upside to having a septic tank is not having to pay sewerage fees to the water company. The downside is having to maintain the tank, which includes emptying the tank as needed. Sometimes your tank will become full before you expect it to. Maybe you had extra family members visiting during the summer, or you were just home more often. When this happens, there will be a few signs you can recognise that will let you know that your tank needs to be emptied.

Empty your septic tank every three years if there are no problems. If you have a large family (five or more members), however, you should empty the tank every two years.

Install risers in your septic system. This allows you to keep an eye on your tank without having to constantly call an inspector to look at it. Just open the lid and check the tank every couple of months. If you begin to notice that the toilet paper and solids within the tank are building up, call to have the septic tank emptied.

Check to see if the sludge at the top of your septic tank has come within 30 cm (1 foot) of the outlet tee. If it has, its time to empty the tank. This is also true if the scum layer on the bottom has reached 15 cm (6 inches) below the outlet tee.

Check for indications that your septic tank is full. These include toilets and sinks that begin to become sluggish, sewage odours, wet grass near the septic tank, or gurgling sounds in the pipes. If you observe any of these, it is time to have your tank pumped.

Check that you do not have a blockage in one of your pipes if the plumbing completely backs up. If you do not have a blockage, it is time to have your septic tank emptied.


If your well water tests positive for bacteria, it may be because your septic tank is full. Check the septic tank, and have it drained if necessary.


Septic tank additives may help break down some of the sludge in your septic tank, but they should never be used to replace pumping the septic tank on a regular basis. Do not dispose of nappies, wipes, tampons or cigarette butts in your toilet. These will clog the pipes going to the septic tank, causing all kinds of problems.

Things You'll Need

  • Risers
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Alicia Bodine has been a professional writer for 13 years. She has produced thousands of articles for online publications such as Demand Studios, GoBankingRates and WiseGeek. Bodine is passionate about gardening, travel, education and finance. She has received awards for being a top content producer.