What is the primary role of anaerobic bacteria in a septic system?

The primary role of anaerobic bacteria in a septic system is to decompose solids. These bacteria thrive in environments without oxygen and are essential for the breakdown of organic matter contained in wastewater. As septic tank contents settle, solids accumulate at the bottom, and anaerobic bacteria work to digest these solids, facilitating the conversion of waste into simpler substances. This decomposition process is crucial for reducing the volume of waste in the tank, preventing the buildup of sludge, and allowing for more efficient operation of the septic system. By breaking down solids, these bacteria help maintain the proper functioning of the system and ensure that the effluent that eventually exits the tank is relatively treated before it moves into the drain field for further filtration and percolation into the soil.