What is the main role of the outlet pipe in a septic tank?

The outlet pipe of a septic tank plays a crucial role in managing wastewater treatment. Its primary function is to direct the treated effluent from the septic tank to the drain field, also known as the leach field. Once wastewater enters the tank, solids settle at the bottom to form sludge, while lighter materials, such as fats and oils, float to the top, forming scum. The treated effluent, which is the liquid layer above the sludge, flows out through the outlet pipe.

This flow is essential for the proper functioning of the entire septic system, as it ensures that only partially treated water is released into the drain field, where it undergoes further filtration and treatment through the soil. This process helps to safeguard groundwater quality and protects against contamination. Therefore, the outlet pipe is integral for transporting the effluent to the area where it can be naturally processed by the environment.