The government of Singapore is spending $10 billion Singapore dollars ($7.2 billion)tocomplete an underground sewer system in the city-state.

The pipeline, dubbed the “underground superhighway,” is 3- 6 meters in diameter and buried 35- 55 meters underground. It will collect wastewater from households and factories and transport it to treatment plants, which will be used mainly for industrial and air-con cooling purposes.

“For us in Singapore, used water is a source of good water. We do not waste a drop of it,” saidNg Joo Hee, chief executive of the Public Utilities Board.