The sequence of treatment processes through which wastewater passes is usually characterized as: preliminary, primary, secondary treatment and tertiary treatment. This discussion is an introduction to advanced treatment methods and processes. Advanced treatment is primarily a tertiary treatment. A number of different unit operations are used in various configurations to make up an advanced wastewater treatment system. The particular situation determines the most applicable process design. Here is what is discussed: 1. SEQUENCE OF PROCESSES, 2. POLISHING PONDS, 3. POST-AERATION, 4. MICROSTRAINING, 5. FILTRATION, 6. ACTIVATED CARBON ADSORPTION, 7. PHOSPHORUS REMOVAL, 8. LAND APPLICATION SYSTEMS, 9. NITRIFICATION, 10. DENITRIFICATION, 11. THREE-STAGE BIOLOGICAL SYSTEMS, 12. ANAEROBIC CONTACT PROCESS