wikipedia: LD50 (median [lethal] dose) 1090 mg/kg (oral, rat)[1] (a gram per kilogram is fairly non-toxic. NaCl (table salt) LD50 is ~3gram/kg)

[1] https://en.wikipedia.org/wiki/Potassium_permanganate

Yup. I heard this di-Hydrogen Oxide can be fatal in very high ingestion cases.

Trying to understand what you're saying -- I believe when you say "their preferences" you mean that people want "basic as-pure-as-possible H2O that they paid for". However, all water that we drink is purified by a wealth of processes. That's not pseudoscientific, that's real science. Our purification is the reason we don't get cholera, for example.

If you mean that people want non-pink water, I think that's reasonable. But I also think it's reasonable that the reason the pink color is explained by the actual purifying process. I too concede that the water controlling authorities screwed up by using too much of the chemical, but it seems not in a dangerous amount, and they did well to communicate exactly why, and they also conducted tests to ensure safety of the water, thus effectively following up and checking the potential problems with their screw-up.

As far as government mistakes go, I think this one was relatively mild and handled in an adequate manner.

randomdrake didn't read the article, and saw the top comment was "you can buy tablets to purify water". He assumed, completely incorrectly, that the commenter was suggesting that people should just buy tablets to purify their water. randomdrake was not trying to comment on how essential services should always be held to exacting standards and that any failure. They weren't trying to say that it is unacceptable for water supplies to have even harmless, temporary inconveniences. They just didn't read the article.