The water on the flight was probably nothing more than bottled Argentinian tap water.

Tap water is treated with chemicals to disinfect and also to change pH and solvation potential.

In bottled or tap water, chlorine is often added to extend the shelf life and prevent Legionella and Giardia and other lethal pathogens from multiplying.

The smell was probably because the water was probably chlorinated or chloraminated and recently bottled. Other chemicals likely to be found include phosphates and ozone. Standard water treatment.

You should try drinking freshly treated mains water at a water treatment works - you won't like that either - it is rank!!

The chlorine content reduces the further you get from the treatment works due to reactions within the water mains.

What it won't be is contamination due to the storage of water bottles next to chemicals.

Transfer contamination works by osmosis and would require the water bottles to be actually sitting in a bath of the 'chemicals' for osmosis to take place and even then, not quickly.

If the water bottles were stored close to the 'chemical' bottles, the concentration in the surrounding air would always have to be higher than that it the bottle of water, otherwise osmosis into the water bottle would not take place.