What Is The Difference Between a Septic System and A Sewer System?

A diagram depicting the difference between a septic system and a sewer system.

Every house needs the means to remove the waste products. If there isn’t one either you’re not going to the toilet at home or you’re going to quickly have an issue.

Of course, most houses have systems fitted before you even move in, you may not give it a second thought. But, there are actually two different types of waste systems, the septic system, and the sewer system.

Let’s take a look at the differences.

Sewer Systems

The standard sewer system is a combination of pipes connecting all the internal appliances in your home to the mains drains. In effect, pipes exit the house having collected all the wastewater and waste products. These are directed down the sewer pipes and to the main treatment works.

Once it reaches the treatment center it will be treated and ejected, to continue its journey through the water cycle.

The homeowner is responsible for keeping the sewer system clear from their home to the junction with the main sewage line. It’s a good idea to find a sewer camera for sale should you ever have an issue with blocked sewer pipes.

The Septic System

A diagram of a conventional septic system and the difference between a septic system and a sewer system.

This type of system still uses the same number of pipes inside your home, removing all waste products and water. But, instead of connecting to the main sewer to goes to the septic tank. This is usually buried in the ground outside your home.

There are different types of septic tank. The first is simply a holding tank, it will need to be periodically emptied by a professional team.

The other types of tank treat the wastewater. They use gravity to allow solid waste to drop to the bottom. Bacteria then feed on the waste products, causing them to biodegrade. The clean water then leaves the tank and is usually out through a filter bed.

The water is then considered pure enough to mingle with the normal waterways in your area, effectively being back in the water cycle.

In general septic systems are used in remote areas where hoses are not connected to the main sewer lines. It’s expensive to add a septic tank or to join the waste lines from a house to the main sewer pipe. But, the sewer pipe is certainly more convenient.

You should also note that some public authorities will charge you for disposing of your water, even if you’ve cleaned it before pumping it into the water supply.


In general sewer systems need very little maintenance, providing you only put approved items through the toilet system. If there is a blockage a sewer camera and drain rods will be enough to clear the issue.

However, the septic system will need to be periodically emptied. If it isn’t the solid waste can build up, causing blockages and allowing the system to backflow. That’s not a pleasant thought for your home.

Providing you look after it, a septic tank will give you very little bother during years of service.

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