According to Singapore’s National water agency PUB the water treatment process at its Bedok plant takes six steps, two of which involve an enhanced disinfecting technology called ozonation. When infused with water, ozone kills bacteria and micro-organisms like algae and plankton which float on the water surface initially.
A coagulant called aluminium sulphate is then used to clump the dead particles. Due to their combined weight, the dead particles sink to the bottom of the tanks, leaving clarified water at the top. At this point, the water looks relatively clean, but it will go through three more steps to ensure it is safe to drink.
Ozone is introduced to the process once more, this time as a disinfectant. The ozonated water is then passed through filters to remove finer particles. To sustain the disinfection, chlorine is added, together with lime and fluoride.
This process provides multiple barrier water treatment system which is combined with monitors that follow the water from the source all the way to our tap.
Bedok Waterworks is one of two plants in Singapore that have been using ozonation for more than two decades.