Singapore, Asia’s economic hub, has a problem: The city-state lacks a secure water supply. The solution: recycled wastewater will soon cover half of the demand.
Singapore is a city-state where the superlative stands out: the banking mecca, known as the “Switzerland of Asia”, has the highest density of millionaires in the world. The economic environment has a great flow of investment. The country has the best health and education systems in the region. And last but not least, the republic benefits from its reputation as one of the cleanest and safest cities in the world. This is reflected in the architecture. Modern and luxurious homes rise so high that they seem to reach the sky. However, the wealthy country lacks a natural resource that is obvious to other countries: water.
Day by day, Singapore has to import millions of litres of drinking water that come from neighbouring Malaysia through pipelines, since it does not have its own sources of freshwater. So much so that the Food and Agriculture Organization of the United Nations described Singapore as a country with “water shortages”. The island state urgently needs alternatives.
The need for different sources
In addition to imported water, which covers about 30 percent of total demand, Singapore obtains the precious “blue treasure” from three other sources. Rainwater is one of them. Annually, up to 2.4 meters of rainfall fall in the country with a tropical climate. The world average is little better than a meter. Altogether 17 reservoirs cover another 30 percent of Singapore’s water demand. However, the country the size of the German city of Hamburg has reached its limit in terms of available space and digging to build more reservoirs would create a problem.
George Madhavan of the Public Services Board (PUB), the national authority for water management and environmental protection explains: “In larger countries, where there are lakes and rivers, it is easy to secure the supply of fresh water They also have enough space to collect and store water. Singapore, because of its surface, does not have those advantages. ” Hence, other solutions must be found. Desalination of seawater is one more option, however, due to the high costs of the procedure, it represents only 10 percent of the total water supply. In 2003, a much more cost-effective and efficient system for processing this valuable resource made its debut in Singapore: high-quality recycled water (called gray water) with the promising name “NEWater”.
Wastewater is made “NEWater”
Recycling wastewater is nothing new. Israel, Spain, the Scandinavian countries and the USA They are known pioneers in the field. However, Singapore’s “NEWater” project has no international comparison. This covers approximately a third of the country’s demand and its projection is to cover more than half of the total demand until the year 2060.
The four national water treatment plants produce 430 million litres of water a day. The wastewater, once recycled, is mainly used for industrial production and refrigeration. A small portion of it is also mixed with nutrient-rich water that is stored in rain tanks. Once processed, it is bottled. The water bottles are not for sale and according to the Ministry of the Environment, there are no plans to sell them in the future. Rather, they are distributed free of charge during major events. The aim is to publicize this ambitious project. The government generally promotes the project by spreading a lot of information about NEWater: So much so that there is a visitor center and guided tours are offered every day.
NEWater Anlage, Singapore
The first of the four NEWater Aufbereitungsanlagen plants became operational in 2002.
About five percent of “NEWater” also enters tap water. This occurs especially during the dry months when the reserves in the rain reservoirs decrease rapidly, making it necessary to inject recycled gray water.
“Thanks to NEWater we are less dependent on weather conditions. Ultra-clean, high-grade recycled water is a Singapore sanitizing services success story and one of the pillars of our sustainable water management,” said Madhavan.
The technology is well established: used and contaminated water is “disinfected” through filtration systems. It is also subjected to reverse osmosis through which it passes under high pressure through a thin membrane that separates the dirt particles from the water. Then ultraviolet rays kill bacteria and disinfect the liquid.
The result is drinking water that exceeds even the standards of the World Health Organization.
For this small country at the southern tip of the Malacca Peninsula, its own water supply is not only an economic necessity but also a strategic priority. In 2061, the water supply contract with neighboring Malaysia expires. By then, Singapore wants to have a separate water source thanks to the NEWater plan.
A versatile model for the future
The Singapore experience is a model for the Asian region in the Pacific. Australia has also been conducting wastewater recycling projects for several years, although it does so for other reasons: “It is necessary to have a constant supply of water to be prepared for the uncertainties of our climate cycles between floods and the dry season A single source of water cannot guarantee the security of supply, “says Marc O’Donohue, head of the Australian Water Recycling Center of Excellence, a Brisbane-based government research institute.
Besucher in der NEWater Fabrik, Singapore
Informing the Public: The NEWater Visitor Center explains how clean water emerges from sewage.
Another challenge that everyone working in wastewater processing has to overcome is the widespread low acceptance of wastewater as a source of drinking water. O’Donohue argues that it is, therefore, necessary to strengthen consumer confidence. The advantages are obvious: “The quality of the water can be easily adjusted in the treatment process, depending on its destination, whether it is used for agriculture, as drinking water or for the production of high-tech products.” On the other hand, in desalination processes, it cannot be graduated in this way. Furthermore, thanks to the many nutrients and energy sources, carbon is also a valuable and versatile resource.
Kartik Chandran, an environmental engineer and professor at Columbia University in New York, believes that recycling water has more advantages. “Aside from reducing total water consumption, the greatest added value of wastewater is that it is a locally available resource. This is particularly beneficial for remote communities. Where fertilizers are too expensive or just not available, food security can be improved by recycling wastewater by specifically regulating nutrient waste. In industrialized nations, recycled greywater could also be used as a source of chemical and hydraulic energy. ”
In other words, wastewater recycling is a versatile model for the future, and not only for large cities like Singapore.