What Are the Different Types of Septic Systems?

What Are the Different Types of Septic Systems?

Learn about the most commonly-used types of septic systems

By Robert Ferguson

New septic tank system for a residential home
Photo by iStockphoto.comBookmark and Share

The three most popular septic tank systems are basic gravity systems, mound systems and aeration systems. Different regions and varying soil types determine the best type of system to use. Designing a septic system is complicated business. It is best to let septic tank professionals design and install the system that best fits the situation. They know the local building codes and zoning requirements and have the equipment needed to install these systems.

Gravity Systems

Most standard gravity systems work by waste entering a septic tank where organisms break down the waste allowing solids to settle on the bottom and the effluent, or fluids, to rise to the top where they are diverted into a drain field. The drain field consists of pipes placed over a 3 foot layer of sand and soil. The effluent drains through these pipes, passes through the sand or soil layer and into the ground below. These tanks require pumping to remove the solids on a regular basis depending on their amount of use.

Mound systems

Mound septic systems use an underground septic tank where household waste enters a tank. Solids settle to the bottom and fluids are diverted to a secondary tank and pumped into the mound. The mound, built above the normal grade, consists of soil and sand placed into layers. The mound is nothing more than a big filter that if landscaped can offer another dimension to the terrain. Place the mound in an area that does not experience high traffic. This will cause the mound's soils to become compacted, making it harder for the effluent to drain into the soil underneath and requiring costly repairs.

Aeration systems

Aeration systems are also known as aerobic septic systems. With aeration systems, air is injected into the septic tank. Because the organisms that break down the waste thrive in oxygen, they do their job more efficiently. Advantages of these types of systems are longer system life, cleaner water drained into the ground and an overall cleaner tank system. Disadvantages are the pumps increase electricity usage, require routine maintenance and can break down.

About the Author

Robert Ferguson is a licensed building contractor with more than 30 years of experience, focusing primarily on residential remodeling, repair, renovation and construction.

Related Guides

Installing Concrete Septic Tank

How to Select a Septic Tank Contractor

When you are installing a new septic tank system or need repairs on your property's drainage system or garbage disposal, work with a reputable and experienced septic tank contractor.... Read More

Plan your Home Maintenance

Sign Up

Already have an account? Log In

Log In with your Facebook account.
We’ll never post without your permission.

Create a DexKnows account:

At least 6 characters
By clicking Sign Up, you agree to the Terms of Service and Privacy Policy. You'll receive the DexKnows Tips email newsletter as well as email updates about your account.

Please share the issue you encountered with our search

I am a(n):


Please check at least one issue checkbox.