Septic Tanks 101: What You Need To Know

Posted on: 12 March 2015

Whether you already have a septic tank or are interested in getting one installed, the most important thing to understand is the maintenance process. Here is an introduction to the subject to help you get started.

What Exactly Is a Septic Tank?

You probably know that a septic tank is a type of waste disposal system. However, in order to keep one running and effective, you need to understand exactly what it is that goes on inside a septic tank.

A septic tank is a miniaturized sewage treatment facility that holds a specific blend of minerals and bacteria. These elements break down certain types of waste, such as human excretions.

To aid in this process, there are several distinct layers which must absolutely be maintained.

The Layers

  • Scum: This is a layer of oils and grease that rests on top of the other layers. As your septic tank breaks down various waste materials, this layer will grow in size. If this layer becomes too thick, then several key components of your tank will clog. This will result in a non-functioning septic system that must be immediately tended to.
  • Sedimentation Zone: Below the scum zone is the sedimentation zone, which primarily consists of water. It is very dirty water that is used to move solids and heavier liquids through the system. As waste moves through the sedimentation zone, gravity will pull the heavier elements downwards into the sludge.
  • Sludge: This is where all of the actual waste ends up, in a solid mass at the bottom of the septic tank. If this layer grows too large, then it can prevent the septic tank from functioning. Therefore, you will need to clean out the tank from time to time.


In terms of day-to-day maintenance, all you really need to do is to check the various plumbing connections if you have a problem and to measure your scum and sludge layers from time to time. Obviously if the waste from the toilet isn't getting to your septic tank you have a problem and might need to call a septic tank repair professional. An inspector will be able to help you identify the layer sizes and to determine whether you need a thorough inspection of the interior.

Watching What You Flush

Since the septic tank relies on a complex system of bacteria and other substances to break down waste, you don't want to flush anything that could disrupt this balance. Specifically, food, paper products, and grease can all back up your system. You do not want to pour drain cleaner into your septic tank, since that can destroy the bacteria living there.