The sewage enters the tank, which has baffles at both ends. The baffles control the flow of water through the tank and keep the light materials which float from entering the drainage field. Inside the tank bacteria and enzymes digest the organic material. The lighter components float to the top and the heavy components sink to the bottom. The clear water which is between those two layers is allowed to flow to the absorbtion field where it drains into the ground. Eventually the tank gets filled with the non-digestible materials and that is when it need to be pumped out. If it is not pumped, then the excess material will exit the tank and enter the seepage field where if will coat the seepage pipes and lessen or stop the absorbtion action. If that happens then the field or cesspool will require replacement. k? Why are septic tanks periodically flushed? (for school project)
