If we look at the regions around the world where people with longest life expectancies come from, the main reason for that is the quality of the local water. Extensive research shows that all those regions had one thing in common, soft water with low calcium ion count (between 8-20 mg/l). Long life expectancy is not a phenomena, everyone can live long but the negative factors make our lives shorter. One of those factors is large amount of calcium in drinking water.
In todays day, it is nearly impossible to find water in the whole world that would be not only clean, but would have a perfect chemical consistency. The worst part is that we are used to looking at water as a nature resource used for cooking and drinking and etc. rather than food. If we change our views and start looking at water as main source of health, then we need to start looking into its components and how to prepare it just like we would food. So instead of term 'water cleaning' we should use 'water making', because instead of just cleaning it from unnecessary and poisonous substances, we need to introduce the minerals that we actually need and lack.
Many water companies proudly state that their water comes directly from the sources in the nature, but really it doesn't say much about the quality of it, because in this day and age many waters found in nature are polluted with chemicals, and the minerals that are needed for your body are ever hardly found, so always check the information on the bottle and make the right choice when buying.