Might also be the result of shitty water treatment or softening, or even the state of the water source, water main and pipes in the building. Some water softening is done via agents like EDTA, which are also used heavily in soaps and detergents.
Yup. I once found out that I had been drinking water from a source that had mold growing all inside the water fountain's plumbing itself. It explained why I constantly felt like shit, given my mold allergy.
