This is what Singapore call its treated wastewater. There are five NEWater plants supplying up to 40% of Singapore’s current water needs. The water undergoes a three step process. Microfiltration: Microscopic particles including some bacteria are filtered out at this stage. Reverse Osmosis: Undesirable contaminants are removed here. The water at this stage is high-grade water. Ultraviolet Disinfection: The water passes through ultraviolet light to ensure any remaining organisms are eradicated. Chemicals are added to restore the pH balance. For non-potable use NEWater is used mainly for industrial and air-con cooling purposes, at wafer fabrication plants, on industrial estates and in commercial buildings. The biggest users of NEWater are wafer fabrication plants, which require water quality that is even more stringent than water for drinking. NEWater is delivered to industrial customers via a dedicated pipe network. During dry periods, NEWater is added to reservoirs to blend with raw water. The raw water from the reservoir is treated at the waterworks before it is supplied to consumers as tap water. This is known as indirect-potable use. More information here.

NeWater – Singapore – ech2o newsletter snippet