Abstract: A self-contained sewage treatment system and method includes a first waterless treating tank operable to separate feculent solids from raw sewage influent in a suspended bio-mass for effective aerobic bacterial digestion in this tank with the outlet of the waterless tank connected to the inlet of a septic tank where sedimentation of the smaller entrained organic particles in the liquor leaving the waterless tank can occur and undergo anaerobic bacterial digestion. The system can include pipe means for distributing the clear liquor from the septic tank in a leach field where it can be disposed of in a safe, pollution-free and environmentally acceptable manner without deleterious effects. Because the method of treatment effectively removes all of the organic solids from the raw sewage influent by using aerobic digestion followed by anaerobic digestion in sequential steps, the clear liquor leaving the septic tank will be environmentally safe and free of all entrained organic matter.