Water Recycling Pipelines

All water is recycled. Every drop of water on Earth has been recycled many times through nature’s own purification systems. Nature does it using biology, and modern treatment plants work by speeding up nature’s own processes in a controlled environment.

The most common water recycling method is called the Return Activated Sludge process. It is primarily a biologic system, but also uses basic physical and chemical principles to remove contaminants from water. Use of mechanical or physical systems to treat wastewater is generally referred to as primary treatment, and use of biological processes to provide further treatment is referred to as secondary treatment. Advanced secondary treatment usually involves applying chemical systems in addition to biological ones, such as injecting chlorine to disinfect the water. In most of the United States, wastewater receives both primary and secondary treatment. Tertiary treatment methods are sometimes used after primary and secondary treatment to remove traces of chemicals and dissolved solids. Tertiary treatment is expensive and not widely practiced except where necessary to remove industrial contaminants. The Return Activated Sludge process takes roughly 18-24 hours to turn raw sewage into a valuable resource.