[mabarker1]

Used primarily to reduce Taste and Odor in Surface Water Treatment Plants or the occasional NASTY Ground Water Well.

[Kipp]

Danville, California, had blue water, which turned out to be from copper. Here’s a very long (and interesting) account of how he identified and solved the problem.

http://www.pushback.com/Wattenburg/bio/BlueWater.html

[Pontiac]

permanganate is a strong oxidizer so was it used in cleaning the water treatment equipment?

It solidifies (oxidizes) dissolved iron, manganese and hydrogen sulfide so that it can precipitate or be filtered out of hard water.

Often followed by ferrous sulfate as a flocculant that makes the particles clump up and fall out of suspension.