Which is a function of the septic tank in a septic system?

The function of the septic tank in a septic system is to store and treat wastewater. When wastewater from a home or building flows into the septic tank, it undergoes initial treatment through a process of physical and biological processes. The tank allows solids to settle at the bottom, forming sludge, while lighter materials, such as grease and oils, float to the top, creating a scum layer.

This separation process is essential for reducing the overall volume of waste and for preparing the wastewater for further treatment. The partially treated liquid effluent then flows out of the tank and into the drain field, where it is further treated by soil microorganisms. This progression is crucial for maintaining a safe and effective waste management system.

On the other hand, options that suggest the septic tank's functions as providing drinking water, capturing solid waste only, or enhancing soil fertility do not accurately reflect its primary role in a septic system. Septic tanks are designed specifically for the management of wastewater, not for producing potable water or enhancing soil fertility directly.