All the waste from your toilet, sink, shower and washing machine enters into your underground septic tank, which is a cement or plastic container ranging in size from 1000 gallons to 2500 gallons. The septic tank collects all the waste made up of both liquids and solids. The tank is constructed with baffles that are designed to contain the solids in the tank where bacterial action helps break down the solids. When operating properly, once the tank is full of liquid, each time additional liquid and solid waste enters the septic tank the solids remain in the tank and the liquid waste, or effluent, will exit the tank and flow into a D-Box and then into your leach field. Your leach field is usually constructed of stone and pipe, cement or plastic chambers, Enviro Septic, Eljen, drywell or some other form of system that takes the untreated liquids or effluent and stores it until it is absorbed into the ground. The bottom of your leach field should be designed to be at least four feet above the ground water. As the effluent waste flows down through the ground it is filtered and cleansed before it reaches the ground water below.