What is the main purpose of a septic tank in a septic system?

The main purpose of a septic tank in a septic system is to treat wastewater before it enters the drain field. This function is critical in the overall operation of the septic system, as it allows for the initial separation and breakdown of solids and liquids present in the wastewater.

In the septic tank, heavier solids settle to the bottom, forming sludge, while lighter materials, such as grease and oils, float to the top, creating scum. The liquid layer in between, which contains partially treated wastewater, flows out into the drain field where further treatment occurs as it percolates through the soil. This process helps to reduce harmful pathogens and pollutants before the effluent re-enters the groundwater supply.

By focusing on the treatment aspect, the septic tank plays a crucial role in protecting public health and the environment by ensuring the wastewater is adequately processed before further treatment in the drain field.