What is a septic system? The individual parts of a septic system consist of the septic tank, a distribution box and a drain field (also called leach lines). The septic tank contains baffles, which prevent any scum that floats to the surface and sludge that settles to the bottom from passing out of the tank. From the septic tank, the liquid waste flows into a small distribution box where it then flows out into several pipes.
These pipes then deliver the liquid waste into a small area known as the drain field, or leach lines. The soil acts as a filter to remove any small amounts of solids that may be carried along with the liquid. The sludge in the bottom of the tank must be pumped out periodically to prevent backup in the house and to keep any excess sludge from getting into the leach field.