What is the function of a septic tank?

The function of a septic tank is to treat and disintegrate sewage using bacteria. When wastewater from a home flows into the septic tank, it is separated into three layers: solids, liquid, and scum. The bacteria present in the tank help break down the organic matter in the sewage through a natural biological process, facilitating its decomposition. This process effectively reduces the volume of waste and helps clarify the effluent that is eventually released into the drain field for further treatment in the soil.

This option is the most accurate because septic tanks are primarily designed for the breakdown and treatment of sewage and waste, rather than any other functions such as storing rainwater or filtering drinking water. The tank handles all household wastewater, not just kitchen waste, making it essential for managing residential sanitation.