Water – it’s essential for life. We drink it every day and use it for many other things. In Singapore, drinking-quality tap water is provided all over the country, making bottled water and boiling of water unnecessary most of the time (PUB, 2019). But does this mean water pollution does not exist in Singapore? In this post, we will answer this question and also explore how urban water pollution exists in many cities all over the world.
Water Pollution.
Urban cities face many sources of water pollution (Figure 1).
Figure 1: Sources of Water Pollution (FilterWater, 2013)
In particular, the problem of urban run-off is serious in many cities. During urbanization, surfaces are covered with concrete, leaving little area exposed to natural soils. These concrete surfaces prevent pollutants such as oils, chemicals and fertilizers from being absorbed into the ground and are instead washed off by surface runoff into rivers and reservoirs (Chaudhry FN & Malik MF, 2017). Furthermore, Wright et al. (2011) found that as rainwater comes into contact with concrete – be it from the ground, pipes or storage areas – it may dissolve, or leach, the minerals present within the concrete, resulting in urban stream waters having 10 times more bicarbonate and 6 times more calcium than non-urban stream waters.
As Strokal et al. (2021) put it, urbanization itself is a large source of water pollution and will continue to be in the future. Under the most likely SSP2 “Middle of the Road” scenario for the future where the world continues developing following historical patterns of uneven development (KC & Lutz, 2014), Strokal et al. (2021) suggest that the world would house 9 billion people by 2100, of which 80% would live in urban areas, numbers which have dire consequences when it comes to water pollution.
Figure 2: River pollution in 2050 and 2100 following different SSP scenarios (Strokal et al., 2021)
In Figure 2 above, Modurb-Modwwt reflects the SSP2 scenario where there is moderate economic development and urbanization and moderate wastewater treatment capabilities. In the short term, many rivers globally will likely become extremely polluted with more than a 30% increase in 5 pollutants present in the water (Figure 2). Pollutants include microplastics (to be discussed in later posts!), Cryptosporidium (a diarrheal-causing parasite), nitrogen, phosphorus and triclosan (a chemical ingredient in many products) (Strokal et al., 2021).
What this means is that there will be less water security and less access to safe, drinking-quality water, especially for developing countries. As former Chief Strategy Officer & Global Ambassador for Water with The Nature Conservancy, Giulio Boccaletti, puts it
No nation has managed to achieve prosperity without first delivering “water security”.
Cities contribute much to the problem, but the good news is, they can also be a part of the solution. Simply having more trees and vegetation can reduce the amount of storm runoff over concrete surfaces. Many cities have begun incorporating green infrastructure, such as green roofs, to manage stormwater onsite. In 2011, Philadelphia announced a 25-year programme, termed Green City, Clean Waters (GCCW), which aims to incorporate green stormwater management infrastructure into the city design over 25 years, reducing water pollution caused by sewage by 85% (American Planning Association (APA), 2015). Rainwater is captured, used to irrigate trees and subsequently returned to the groundwater (APA, 2015). Reducing runoff would be beneficial for the reduction of phosphorus levels in the water, as Hobbie et al. (2016) report, while other measures such as reducing the use of fertilizers would be needed to reduce nitrogen levels in the water.
This brings us back to our question in the beginning, is there water pollution in Singapore today? The answer is yes. As a 100% urban city with high population density, Singapore similarly faces the problem of water pollution due to sewage and trash – it simply has the means to deal with it. Singapore boasts an impressive sewage system that collects 100% of all used wastewater from the surface, which is then treated to become NEWater (which is safe, treated, used water) (Tortajada, 2007).
Even more impressive is the number of workers (almost all of them migrant workers) working round the clock to keep our rivers free of pollution and trash. When storms occur and drainage capacity is exceeded, trash spills out of our sewage system onto river surfaces but in a few short days, is removed by workers.
As Tan (2016) rightly puts it, Singapore is ‘not so much a clean city as it is a “cleaned” one’.
Water pollution does exist. It is simply hidden from the public eye.
References