Majority of the earth surface is covered with water. That is about 2/3 of the earth. I learnt this from geography back then.
Having the majority of the earth covered by water doesn't mean that water is available to all the inhabitants of the earth.
At least not always in the way and manner it is needed.
Some places have water in abundance all year round, year in year out while there are places where water is gold always and also places where water becomes gold occasionally.
What do I mean?
There are places where water is scarce all year round especially water for drinking and for cooking. While some other places, the scarcity is occasional and usually occurs following a particular event.
While some areas, the lucky ones have abundant supply of clean water all the time.
Currently, the town I reside falls into the second category.
I just returned from fetching water and hence motivated to write on this topic.
Picture is mine
My source of water for drinking is sachet water from the water bottling companies. This is because it is usually the safest in my environment. When it comes to cooking and other water requirements, like bathing and washing, I go to the water tank which is usually filled up by the borehole when it is pumped. This is equally clean but not always available because it depends on electricity supply with which the water is pumped.
If there is no electricity for sometime, this source of water would be cut off from me but as long as I have my money in my pocket, I can easily get the bag of sachet water which serves me for drinking.
I don't need to treat my water further because it comes to me in good condition.
Once, I bought a bag of sachet water and realised that the water had taste. I just took note of the company that produced it and discarded the bag while making sure I never buy it again even if it was the only available bag of water.
While this is my experience, some other places have to ensure they treat their water because it doesn't come in optimal condition.
The various approaches to water treatment include but not limited to; boiling, filtration, use of alum, distillation, etc. to name a few.
I have also heard of people that combine these various approaches to achieve safe water. That is to say that they use alum before boiling and then filtering.
I think that regardless of your location and access to water, once you ensure that your water has the following physical qualities, you are good to go;
Colourless; it should not have any colour whatsoever.
Odourless: safe water should have no smell.
Tasteless; should not have taste, even if it is a sweet taste. Except of course you are the one that added the sweetener intentionally and is aware of your added ingredient and it's safety.
Once your water meets the criteria, you can proceed to use it for domestic purposes.