In the last 20 years, the Singapore government has spent $2 billion on sewerage infrastructure alone. The present system includes six sewage treatment works, 2,585 kilometers (1,600 miles) of gravity sewers and 134 pumping stations located throughout the island.

Modeled on state-of-the-art systems worldwide, the new system ultimately will comprise 48 kilometers (30 miles) of deep tunnels and 170 kilometers (106 miles) of link sewers that convey sewage to deep tunnels by gravity, eliminating the need for more than 100 existing pump stations. The system also includes a wastewater reclamation plant located on reclaimed land away from residential areas, as well as a 5-kilometer-long (3-mile-long) deep-sea outfall into the Straits of Singapore.