What is the main function of a septic system?

The primary function of a septic system is to filter and treat wastewater before it is released back into the environment. When wastewater from household activities, such as bathing, cooking, and flushing toilets, flows into the septic tank, the system allows solids to settle at the bottom, forming sludge, while lighter materials like grease float to the top, creating scum. The effluent that is cleared from the tank then flows into the drain field, where it is absorbed into the soil. This process naturally filters the wastewater, allowing harmful pathogens and nutrients to be treated by the soil before entering the groundwater.

Other functions mentioned, such as recycling gray water for irrigation, venting sewer gases, or monitoring gas consumption, do not represent the main purpose of a septic system. While gray water recycling might be a separate system designed for water conservation, it does not relate to the basic function of a septic system. Similarly, venting sewer gases pertains more to building plumbing systems rather than the septic system itself, and monitoring gas consumption is unrelated to wastewater management. Thus, the highlighted role of filtering and treating wastewater is the central aspect of what a septic system is designed to achieve.