What is the primary function of a septic tank?

The primary function of a septic tank is to treat sewage. When household wastewater enters the septic tank, it undergoes a separation process where solids settle to the bottom and form sludge, while lighter materials like grease float to the surface as scum. The tank provides an environment for anaerobic bacteria to break down these solids, rendering the wastewater less harmful before it is released into the drain field for further treatment through soil filtration.

The design of a septic system is specifically aimed at managing and treating domestic sewage, ensuring that harmful pathogens and contaminants are reduced before the effluent reaches the groundwater or surrounding soil. This process is crucial for protecting public health and maintaining the environment by avoiding pollution of surface and groundwater.