Regardless of how clean your drinking water looks, there is no guarantee that it is pure 3a molecular sieve and germ-free. It could have microscopic pathogens that cause diseases, new age contaminants like lead and arsenic or a very high level of TDS (Total Dissolved Salts).
Molecular sieve
Across 8 major cities in India, Water treatment equipment water- borne diseases like cholera, jaundice and typhoid accounted for 77% percent of all the diseases in India. The survey also threw light on the fact that the TDS levels are way above the permissible level in many regions in India, including cities like Mumbai, Delhi, Bangalore.
You may think that boiling your water before you drink it is good enough. However, this is far from the truth. Boiling only provides protection against microbial contamination caused by bacteria, virus, etc. it does not remove dangerous chemicals/new age contaminants like lead, pesticides and physical impurities like mud, dust, rust, etc.