Reclaimed water

Main article: NEWater

Bottles of NEWater for distribution during theNational Day Paradecelebrations of 2005 atMarina South

NEWater is the brand name given to reclaimed water produced by Singapore's public utilities. More specifically, it is treated wastewater (sewage) that has been purified using dual-membrane (via microfiltration and reverse osmosis) and ultraviolet technologies, in addition to conventional water treatment processes.

As of 2008, there are five NEWater factories, located at the Bedok, Kranji, and Seletar, Ulu Pandan and Changi Water Reclamation Plants, producing 50 million imperial gallons (230,000 m³) per day. Some of the NEWater is used at wafer fabrication plants and other non-potable applications in industries. The rest is fed into nearby reservoirs. NEWater is currently able to meet 30% of Singapore's water requirements.^[5][6]

The Deep Tunnel Sewerage System (DTSS), a 48-km long deep tunnel sewer that runs 20 to 55 metres below ground, channels used water to a centralised water reclamation plant for treatment. The treated used water will then be discharged into the sea or 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. Until DTSS will be completed, wastewater is collected through a sewer system that includes 139 pumping stations that pump water to six wastewater treatment plants. These pumping stations and plants will be decommissioned when the DTSS will become operational.^[7]

Supply provided by water catchment areas

The barrage of the Marina Bay reservoir.

Two thirds of the country's surface area are classified as partly protected catchment areas with certain restrictions on land use, so that the rainwater can be collected and used as drinking water. As of 2010, the water supply system included 19 raw water reservoirs, 9 treatment works and 17 service reservoirs for treated water. The largest reservoir, the Marina Bay reservoir inaugurated in 2008, is in the estuary of a river that has been closed off by a barrage to keep the seawater out. Two similar barrages are due to be completed in 2011 and will form the Punggol Reservoir and the Serangoon Reservoir.

Water sources

The water resources of Singapore are especially precious given the small amount of land and territory in Singapore's geography while having a large urban population in thecity-state. Without natural freshwater lakes, Singapore relies on four water sources:

• rainfall, collected in reservoirs or water catchment areas (about 20% of supply in 2010),
• Imported water from Malaysia (about 40% of supply),
• Reclaimed water (producing NEWater) (30% of supply), and
• Seawater desalination (10% of supply).

This "four tap" strategy aims to reduce reliance on supply from Malaysia by increasing the volume supplied from the three other sources, or "national taps".

History

Singapore's first reservoir was the MacRitchie reservoir, which was built by the British in 1867. Subsequently, as Singapore developed into a modern city, more sources of water were needed to sustain the city’s growth. Thus two local reservoirs were added to the rapidly modernising colonial city. After independence in 1965, the Public Utilities Board took over the control of basic supplies including water. From then on, there have been many developments and improvements to increase the water supply for Singapore. The 1960s and 1970s saw great development for Singapore. In order to maintain that, many big water projects were embarked upon to increase the water supply. Examples of these projects included the Kranji-Pandan Scheme, the Upper Pierce Project and the Western Catchment Water Scheme.

In 2001 the Public Utilities Board, which had previously been in charge of water supply only, was given the responsibility for sanitation as well which had previously been directly provided by the Ministry of Environment. The change facilitated the implementation of an integrated water management approach. In 2002 Singapore inaugurated its first reclaimed water plant after a monitoring period of two years to ensure safe water quality. In 2005 it opened its first desalination plant. By the time the long-term water supply agreement with Malaysia expires in 2061, Singapore wants to be self-sufficient in terms of water supply, with reclaimed water meeting 40% and desalination 30% of its needs in addition to the 20% supplied by internal catchments.

Water supply and sanitation in Singapore is characterized by a number of achievements in the challenging environment of a densely populated island. Access to water is universal, affordable, efficient and of high quality. Innovative integrated water management approaches such as the reuse of reclaimed water, the establishment of protected areas in urban rainwater catchments and the use of estuaries as freshwater reservoirs have been introduced along with seawater desalination in order to reduce the country's dependence on imported water. In 2007 Singapore's water and sanitation utility, the Public Utilities Board, received the Stockholm Industry Water Award for its holistic approach to water resources management.[3]