'Very, very pink' tap water in Alberta town
A lot of the posts here seem to be missing something important: permanganate is an EXTREMELY vividly colored ion in solution. The bright colors of the water in the pictures is about in line with what a 20 ppm permanganate solution looks like. Considering manganese is an essential trace mineral (although it is neurotoxic above a certain point, the amounts in the water are minimal), I doubt there is any real toxic effect caused by drinking the water. Permanganate is a very strong oxidizer, but it is not much stronger than the commonly used chlorine and chlorine dioxide to be of concern (and it's weaker than ozone anyways).The whole reason permanganate is added in the first place is twofold: it oxidizes simple organics all the way to carbon dioxide (think nail polish remover, denatured alcohol), and it oxidizes soluble ferrous iron to insoluble ferric iron. The byproduct of the oxidation, manganese dioxide, is insoluble and if balanced correctly the treatment does not increase manganese levels in the water.