When you need water, it’s simple: just turn on the faucet.

But the water is not free. Your parents know that: they pay the bill!

Yet, there’s water everywhere: in the oceans, rivers, lakes, and when it rains. There’s so much water, we call the Earth the “blue planet”!

So if there’s so much water, why do we have to pay to use it?

Because water that is found in nature is not necessarily pure. It may contain dirt, algae or microbes.