The biggest problem with manganese in drinking water is that at higher concentrations it causes water to be cloudy, rusty, smell bad and have an odd taste. There are no adverse health affects known, but when combined with other dissolved and partially dissolved metals and minerals it can cause serious damage to plumbing. The major damage is caused when these trace metals and minerals collect in the pipes, causing them to corrode, which in turn releases more metals into the water. It can get to the point where the entire plumbing system is blocked by these mineral deposits and has to be replaced. This includes water heaters and any other plumbing fixtures in the home.

When manganese and iron are present at water treatment facilities, they can react with the chemicals used to purify the water. This results in cloudy or oddly colored water, which can have a bad odor as well. Special filtration is needed in this case, using what is known as greensand. This material traps iron, manganese and other trace elements, to purify the water for use. With a private well, testing can tell you if manganese is present in your water, and at what amount. Filtering well water, at the very least, is generally a good idea, to remove sediment and other dissolved minerals. Most drinking water anywhere would benefit from filtering. There are what are known as protected drinking water communities, in which the water treatment is as chemical free as possible. They also take steps to ensure the ground water contamination is kept to a minimum by capping unused wells.