[ddeck]

Singapore has been recycling sewage into potable water for some time now. Although the majority is used in industrial applications requiring very pure water (e.g wafer fabs), some is added to the tap water:

NEWater is mainly used for industrial and air-con cooling purposes at wafer fabrication plants, industrial estates and 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 our reservoirs to blend with raw water. The raw water from the reservoir then goes through treatment at the waterworks before it is supplied to consumers as tap water. [1]

[1] http://www.pub.gov.sg/water/newater/Pages/default.aspx#newat...