How Is Drinking Water Disinfected?
You may not have thought about the water that you drink in your home. In the UK, we’re so lucky that, when we turn on the tap, it’s just there, perfectly drinkable, with all the impurities already removed. How does that happen, though? How is drinking water disinfected? Read on to find out – it’s a fascinating process.
Why Disinfect Water?
The water that comes into our homes in the UK comes from a variety of different sources including:
As you might imagine, this water, open to and out in the elements, will be full of bacteria and debris which, apart from making it dangerous and disgusting to drink, would also be a problem for pipes and drainage systems, particularly in areas that still works on older systems. Therefore, to keep everything working as it should, and to enable us to drink the water, it needs to be disinfected.
The first step when it comes to disinfecting drinking water is coagulation. This is when positively charged chemicals are added to the water which then neutralises the dissolved particles that need to be removed. The particles become able to bind with one another, creating larger particles which are easier to take out. This becomes known as ‘floc.’
The floc settles to the bottom of the tank or area where the water is being held because it is heavier than the water itself. This process – known as sedimentation – means that the floc can easier be filtered out of the water, leaving a purer (although not pure just yet) liquid behind.
The filtration system is made up of filters of different compositions including sand, gravel, and charcoal. The water passes through each filter, the pores of which will become smaller as the process carries on so that by the end, anything that did not become floc has been removed. This could include:
Although the quality of the water in the UK varies from place to place, it is all treated with chlorine. The chlorine kills off the remaining germs that are contaminating the water, making it safe to drink.
Before chlorination happened regularly, it was common for people to catch terrible illnesses from the water they drank including dysentery, cholera, and typhoid. All water that is now sent to UK homes is chlorinated and has been since 1905.
Chlorine is pumped into the filtered water in large tanks using powerful pumps like the Yako Transfer Pump which ensures that chlorine is entirely mixed through the water.
The disinfection process is checked continuously along the way from beginning to end, ensuring that the water you drink is as safe as possible. It is essential, however, for those who drink the water to get in touch with their local water authority if they notice a strange taste, colour, or odour when they drink the water or turn on the tap. By staying vigilant, any problems can be fixed much more quickly so that any disruption to the water that might be caused is dealt with and managed fast.