Water Supply and Sanitation in Singapore - Sanitation

Sanitation

Until 2010, wastewater in Singapore was collected through a sewer system that included 139 pumping stations that pumped water to six wastewater treatment plants. These pumping stations and plants are to be gradually decommissioned while a new system, the Deep Tunnel Sewerage System (DTSS), becomes operational. The Changi Water Reclamation Plant, the heart of the first phase of the DTSS, was opened by Prime Minister Lee Hsien Loong in June 2010. The first phase of the DTSS consists of a 48-km long deep tunnel sewer that runs 20 to 55 metres below ground, channels used water to the Changi Water Reclamation Plant at the Eastern end of the island. The plant has a capacity of 176 million imperial gallons (800,000 m3) per day. Most of the treated used water is discharged into the sea through an outfall, while some of it is further purified into NEWater. The deep tunnel works entirely by gravity, eliminating the need for pumping stations, and thus the risks of used water overflows. At one-third the size of conventional plants, the Changi Water Reclamation Plant is designed to be compact. Centralisation of used water treatment at Changi also allows for economies of scale. In a second phase of the DTSS, the deep tunnel system is to be expanded to the entire island, with a second wastewater treatment plant at Tuas at the Western end of the island.