What does a septic tank primarily do?

The primary function of a septic tank is to separate solids from liquids within wastewater. As wastewater from the household flows into the tank, heavier solid materials settle at the bottom, forming a sludge layer. This natural separation process allows the lighter liquids to float on top, forming a scum layer. This separation is crucial because it helps prevent solids from clogging the drainage system and facilitates the breakdown of organic materials by anaerobic bacteria.

The separation of solids and liquids also ensures that relatively clearer liquid effluent is sent to the drainage field for further filtration and treatment in the soil. Understanding this process is fundamental for any septic system installer, as it influences the design, maintenance, and troubleshooting of septic systems.