TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Components: The microbial ecology comprises one or more of Methanosarcina, Methanothrix, Methylmonas, Methylobacter, Methylocystis, Acetobacterium, Clostridium, Escherichia, Lactobacillus, Propiombacterium, Desulfovibrio, Desulfotomaculum, Desulfomonas, Archaeoglobus, Campylobacter, Pseudomonas, Bacillus, Nocardia, Spirillum, Vibrio, Alcaligenes, Paracoccus denitrificans, or Thiobacillus denitrificans. The second stage comprises an ecology representative of delta plants. The delta plants include one or more of Phragmites, Typha, Arundo, Papyri or Scirpus genera. The delta plants include one or more of Phragmites communis, Phragmites australis, Arundo donax, Papyri aegypti, Scirpus acutus,    TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Method: The biological oxidation is assisted by addition of 30-50 kg of oxygen per 100 m3 of effluent from the second stage. The oxygen is delivered to the third stage by a diffusion system powered by an aeration system having an external energy requirement of less than 12-28 kilowatts per day per 100 m3 of filtrate.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: The third stage comprises an aquatic system adapted to provide biological oxidation of water soluble carbon and nitrogen compounds contained in effluent from the second stage. The fourth stage is adapted to further oxidize carbon and nitrogen compounds using a pump discharging 8-11 liters per minute per m3 of sludge processed per day. The pump uses less than 16 kilowatts per day per 100 m3 of effluent. The fifth stage is adapted to receive soluble oxidized nitrogen and carbon compounds and suspended solids from a preceding stage, and to remove the oxidized nitrogen and carbon compounds and the suspended solids without any external input of energy. The sixth stage adapted to remove remaining carbon and nitrogen compounds, suspended solids, and pathogenic organisms. The sixth stage is configured with a pump designed to discharge 8-11 liters per minute per m3 of sludge and/or septage. The sixth stage is configured to use less than 16-20 kilowatts per 100 m3 of effluent supplied to the sixth stage. The first stage comprises an equalization vessel (130) configured for temperature control and configured for aeration. The equalization vessel comprises a pump for providing aeration. The first stage comprises a microbial ecology of a eutrophic lake bottom. A trickling filter (160) is in fluid communication with the second vessel and configured to provide nitrification and oxygenation of the separated septage, the trickling filter configured with one or more growth nitrifying organisms;