[zzazzdsa]

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.

[oxide]

>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.

Whenever I learn something like this, I always appreciate chemistry a little more. That is absolutely fascinating IMO.

The first thing that comes to mind is what the person who came up with the idea was doing at the time. Sometimes when we are intending to do one thing, we invent a solution to another problem, maybe one we didn't even know we had, along the way.

[jordanb]

For reference:

http://www.caruscorporation.com/resources/content/7/5/images...

[jghn]

Oh thanks.

When I was a kid I was visiting my aunt who lived outside of Denver. I was walking around their property and on the other side of a fence was a stream which was exactly this color. I've always wondered what the deal was

[coldcode]

We used permanganate when I was in grad school to clean glassware of organic residue. Concentrated it is extremely good at it. At such minimal concentration its not an issue.

[ekianjo]

It's also widely used (in chemistry labs) as a titration indicator. Because of its vivid color, you can very easily determine when you cross the boundaries of a specific reaction.

[sametmax]

There is probably not "any real toxic effect" with a small dose taken over a few months in an isolated study.

But what about a small dose taken over years, and interacting with the thousands of small doses of synthetic chemicals we have in our body because of processed food, hygiene products, clothes, surface treatments and medicine ?

This we have no way to know.

There are already so many reasons to get in contact with synthetic chemicals. I think it's sane policy to limit them a much as we can when we can, especially in something as ubiquitous as water.

Yes having drinkable water is essential, but some cities manage to have it with much less additives. It should be the default goal for anything related to public health.

[literallycancer]

>There are already so many reasons to get in contact with synthetic chemicals.

Such a pointless distinction. There are many chemicals that occur naturally and will kill you.

[sametmax]

Anything can kill you. You can kill somebody with a piece of wood, a nuclear device, gaz, light, shock waves, a baby, a golden coin...

And any matter is a chemical. Using "synthetic" as a qualifier allow me to distinguish "fructose" from "paracetamol". You will less likely see important traces of cobra venom in the water.

It's not perfect, but I fail to find a better term.

[jcranmer]

> This we have no way to know.

We do have a way to know. It's called chemistry, and one of the primary goals of chemistry is to be able to predict what sort of reactions will occur in a mixture of molecules. Anyone who takes organic chemistry should be able to tell you how alkenes, alkynes, aldehydes, ketones, ketals, alcohols, aromatics, amines, amides, peroxides, ethers, esters, etc. are likely to react in various conditions, and hopefully what factors promote or retard such reactions.

[empath75]

They didn't add it to the water on purpose.

[sametmax]

I get that but I find strange that in 2017 in modern countries water quality should still be a debate. It should be in the "problem solved" category.

[greenshackle2]

It is a solved problem. A benign mistake happened at one sanitation plant. The city is working to resolve it. How does that make water quality a 'debate'?

[hwillis]

>The town drained its water reservoir and all lines have been flushed, but there may be some residual colour in some systems, the mayor said, adding property owners may need to run their water for a few minutes to clear their service lines.

Why are you worrying about cumulative doses over years, when this problem literally existed for minutes?