What is the primary type of bacteria that breakdown organic solids in a septic tank?

The primary type of bacteria that breaks down organic solids in a septic tank is anaerobic bacteria. These bacteria function in environments where oxygen is absent or very limited. In a septic tank, organic solids are settled at the bottom, creating conditions where oxygen is not readily available. Anaerobic bacteria thrive in these conditions and are responsible for the decomposition of these solids into simpler compounds, which helps in reducing the volume of sludge and promoting the overall functioning of the septic system.

In contrast, aerobic bacteria require oxygen to survive and are more effective in processes like composting or aerobic digestion, but they are not the primary decomposers in the anaerobic conditions of a septic tank. Facultative bacteria can utilize both aerobic and anaerobic processes but are not the main contributors to the breakdown of organic waste in a septic tank environment. Pathogenic bacteria are typically harmful microorganisms that can cause disease but do not play a significant role in the decomposition of organic solids in a septic system. Thus, the role of anaerobic bacteria is crucial in the breakdown processes occurring within a septic tank.