Installing a septic tank generally consists of a tank (or sometimes more than one tank) of between 1,000 and 2,000 gallons in size connected to an inlet wastewater pipe at one end and a septic drain field at the other. Today the design of the tank usually incorporates two chambers which are separated by means of a dividing wall which has openings located about midway between the floor and roof of the tank. Wastewater enters the first chamber of the tank, allowing solids to settle and scum to float. The settled solids are anaerobically digested reducing the volume of solids. The liquid component flows through the dividing wall into the second chamber where further settlement takes place with the excess liquid then draining in a relatively clear condition from the outlet into the drain field.