In the context of septic systems, what does 'effluent' refer to?

Effluent refers to the treated wastewater that is released from a septic tank or treatment system after the solids have settled and been broken down by bacteria. In a properly functioning septic system, the effluent is the liquid that flows out of the tank and into the drain field or leach field. This effluent contains nutrients and microorganisms that have been partially treated, allowing it to be absorbed by the soil and further purified through natural processes.

Understanding the role of effluent is essential for maintaining a septic system, as it helps prevent issues such as backups or environmental contamination when properly managed. The other choices represent different components of the septic system: solid waste and sludge only refer to the solids that accumulate in the tank, while soil used for absorption is part of the treatment process but does not describe the wastewater itself.