A Comparison of Aerobic and Anaerobic Septic Systems

When it comes to septic systems, many homeowners are uncertain about the difference between aerobic and anaerobic systems. This article provides a clear explanation of the two approaches, highlighting their advantages and disadvantages so you can make an informed decision.

What Are Aerobic and Anaerobic Septic Systems? 

Aerobic septic systems use oxygen to break down waste, while anaerobic septic systems do not require oxygen. In aerobic systems, bacteria need oxygen to work, but in anaerobic systems, bacteria don’t need oxygen and it works slowly. In general, anaerobic septic systems are cheaper than aerobic ones and they require more maintenance and produce a higher level of odors. On the other hand, aerobic systems are more expensive but they are extremely effective and don’t generate strong odors.

Advantages of an Aerobic System 

One of the major advantages of an aerobic septic system is that it is a more efficient and effective solution for most septic systems as it does not require a large amount of space for installation compared to anaerobic systems. Additionally, aerobic systems are much less likely to have issues such as backups due to insufficient oxygen and sludge accumulation. Furthermore, aerobic systems produce some of the clearest effluent among all types of septic systems.

Disadvantages of an Aerobic System 

However, aerobic septic systems do come with some disadvantages. Perhaps the biggest drawback is that it requires a more frequent maintenance schedule than other types of septic systems. Because these systems are powered by electricity and because oxygen is crucial to its efficiency, maintenance must be done at least every three months to ensure optimal functioning of the system. Additionally, aerobic systems have higher upfront costs due to the need for additional components such as pumps and aeration chambers.

Advantages of an Anaerobic System

While anaerobic systems cost more upfront than conventional septic systems, they require less frequent maintenance work and their operation is simpler than their aerobic counterparts. Since oxygen is not necessary for anaerobic bacteria to break down sewage, they are more resilient and can better tolerate extreme temperatures compared to aerobic bacteria. Additionally, since no power or electricity is necessary to run the system, operational costs are lower than with other types of septic systems.

Disadvantages of an Anaerobic System

Despite the advantages of anaerobic septic tanks, there are also some disadvantages. The primary issue is that anaerobic systems produce a high level of greenhouse gases, such as methane and nitrous oxide, that can be hazardous to the environment. Additionally, because anaerobic bacteria work slower than aerobic bacteria, they require more regular maintenance and pumping in order to work effectively compared to aerobic systems. Finally, since anaerobic septic systems do not have filters or screens for solid waste particles, larger materials may accumulate over time and clog pipes or tanks.