Iron and Manganese

Iron and manganese are both known to stain the water supply. They can make water appear red or yellow, create brown or black stains in the sink, and give off an easily detectable metallic taste. Although these can all be aesthetically displeasing, iron and manganese are not considered health risks. Fortunately, they can be removed from the water easily. First though, the type of iron that is contaminating the water supply must be determined.

  1. Ferrous iron - The water appears to be clear, but after standing, black or rust colored particles settle to the bottom.
  2. Ferric iron - Water straight from the faucet has a red, yellow, or rusty color to it. This type will also easily settle to the bottom.
  3. Iron bacteria - Plumbing fixtures have a slimy brown, red or green film, or there is a gelatinous sludge in the pipes. Occasionally chunks of this slime can be dislodged from pipes yielding colored water. These bacteria feed on iron found in pipes or fittings.

Treatment for iron is traditionally done using various forms of filtration and/or chlorination. However, water analysis and consulting a professional is recommended. Not only does the form of the iron and manganese matter, but the amount of the metal present as well as hardness, temperature and pH are also key factors. In the case of iron bacteria , a sample should be taken to your local health department or water department for observation. If iron bacteria are present, chlorination may help, but to what extent should be determined by a professional.

If you have additional questions regarding iron and manganese in your water, the web site at North Carolina State University's Cooperative Extension Service is an excellent resource. It includes treatment options, and an enlarged description of what these two minerals will do to your water.

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This page was prepared by S.L. Keyser, UCD EXTOXNET FAQ Team.
June 1997