What typically happens to the solids in a septic tank?

In a septic tank, solids typically settle to the bottom due to gravity. This settling process allows for the separation of solids from the liquid waste, leading to the formation of distinct layers within the tank. The denser solids accumulate at the bottom as a sludge layer, while lighter materials, such as fats and oils, rise to the top to form a scum layer. This separation is crucial for the effective functioning of a septic system, as it prevents solid particles from entering the drain field, which could cause clogs and system failure. Proper maintenance of the tank, including regular pumping to remove the accumulated sludge and scum, is essential to ensure that the septic system continues to operate effectively.