Our planet is actually seventy-five percent water. This is a lot of water. The issue is that a lot of of it isn't drinkable. The treatment of water is supposed to help to sort out this issue at least a bit.
When you look at the body of a human you will see that a large proportion of the body is water. Which means that if you don't drink a great amount of water each and every single day your body is not going to always be working at its optimum capacity. You have to make sure that the water you are drinking is actually water that is drinkable though. You can pick up a lot of issues should you consume just any old water. This is how the treatment of water will come into play.
The treatment of water really does a number of things. An all encompassing name for all these things is probably purification. Water straight from the river or even dam is filled with all kinds of impurities. These impurities need to be removed before the water is considered to be drinkable.
The bigger impurities are going to be things such as leaves and other rotting vegetable as well as animal matter. This sound fairly disgusting, true, but it's a well known fact of life that things pass away in rivers and dams. Mostly it is plant matter as well as creatures like fish, however the odd household animal as well as wild animal will end up in the rivers as well as water systems. These are easily filtered out with bigger rock and sand filter systems. If they weren't filtered out they would truly make you sick because they are a breeding ground for those kinds of bacteria.
Then there are the smaller impurities. These are generally minerals. An excessive amount of certain minerals is not good for you and some may cause things like heavy metal poisoning. They are filtered out by a number of progressively smaller sized filters as well as chemical treatments.
The littlest impurities, the viruses and bacteria and other tiny, single cell microorganisms, have to be removed as much as possible as well. This really is generally done with heat treatments as well as chemical treatments. Not every one of them are eliminated though, they're way too many and too tiny.
Once the treatment of water is finished you have water which is drinkable. All nations have a certain level of purity that should be reached before the water is considered safe for people to drink. The unfortunate thing is that not all nations have water that's actually drinkable and the citizens are reduced to purchasing water in bottles for drinking as well as cooking while washing within the water which comes out of the faucets. This is why it is a good idea to do some investigation on the nations you visit before simply consuming the water which is in the taps. You may just give yourself an upset tummy.
As you can see, the treatment of water is actually extremely important. You don't want to put all of the impurities within river and dam water into your system, just ask some of the African nations what happens if you do that.