How Do Septic Tank Aeration Systems Work?

Advantage and Disadvantage

An aeration system is very similar to a septic system. They both hold waste that comes from bathroom facilities, break it down and send it out into the ground. However an aeration system is more expensive to purchase, costs the owners more in electricity and needs attention more often from service technicians. Because power is needed to run part of the system, power outages that last a great length of time can cause build up that might cause back up, pumping or at the least a service call. Even with these disadvantages, the system is a better set up with cleaner water coming out the other end.


The system itself is made up of a large tank with three compartments within. Each compartment has an opening near the top of the tank for the water to flow to the next chamber. There is a filter in place that keeps large solids from going through to other sections. An aerator is in the middle chamber powered by electricity. There is an access area above ground to get to the workings of the aerator in case it needs maintenance. The third chamber has a sloping floor at the bottom that leans back toward the second chamber and an opening at the bottom connecting it to the second chamber.


The waste water flows into the first chamber, which is called a settling camber. Large solid waste settles to the bottom. Natural bacteria from the body reside in the waste and break it down into smaller pieces. This waste water flows through a filtered opening near the top of the tank into the second chamber. In the second chamber the aeration system mixes up the waste water forcing air into the water. Bacteria from the air enter the water and further break down waste. The water then flows through a second opening near the top of the tank into a third chamber. In this chamber any solids or bacteria that might have made it through, settle to the bottom while water flows out of the tank. The particles that settle to the bottom, fall onto a sloped floor that sends them sliding toward an opening at the bottom and back into the second compartment for more treatment.