How Does A Septic System Work?

So, you may have a septic tank on your property but aren’t sure of how it works. It’s always good to understand how a septic system works so that you can look after it, and that you can understand when it needs repairs or service. Clarington Septic Repairs is always willing to share its knowledge with all of our clients.

How does a septic tank work?

A septic tank digests all of the organic matter and then separates it into two parts; the solids and the liquid. The lighter solids will float to the top and create a “cake like” layer, the liquid will stay in the middle and the heavy waste (sludge) will sink to the bottom. So, in the septic tank, you will end up with three different sections of waste.  The middle liquid layer is what drains out into the drain field, and the rest will need to be pumped out of the septic tank. A septic tank has an inlet pipe that is used to transport the water waste from the house into the tank. The outlet pipe, also called the drain field (leaching field pipe or outlet) is the second pipe. Pre-processed wastewater from the tank moves out through this pipe and spreads evenly through the watercourses and soil. Bacteria that is inside of the tank helps to breaks down the solid, which then allows the liquid to easily separate and drain away.

A step-by-step process of how it all works

So, water from your bathroom or kitchen runs through the main drainage pipe that goes to your septic tank. The underground septic tank then begins the process of collecting the wastewater. It needs to retain this wastewater as long as possible so that any solids can sink down into the bottom of the tank. Once this process is completed, the liquid wastewater will then exit the septic tank and drain into the drain field. The septic tank will need to be pumped to remove the solids every 3-5 years, or as recommended by your local septic tank pumper.

Treatment process

The treatment process of a septic tank is usually quite simple; however, it is important to know how it works. Unlike a sewage treatment plant, a septic tank does not provide any treatment to the wastewater, and therefore it must be discharged into the drainage field. The bacteria found in a septic tank will do their best to break down the sludge or the solid waste at the bottom of the tank. The remaining sludge will build up over time and will need emptying, which is known as pumping.


When you have a septic tank on your property, it is always good to understand what a septic tank is and how it works. When you do, you will ensure that the members in your household do their best to look after the septic system. You will also ensure that you get your septic tank is serviced and repaired when it is required. Call us at Clarington Septic Repairs if you need more information about your septic system.