Iron bacteria are a type of bacteria that derive energy by oxidizing iron or manganese. They are commonly found in soil, surface water, and groundwater. These bacteria can cause problems in wells and plumbing systems as they produce a reddish-brown (iron) or black-brown (manganese) slime that can clog plumbing and cause an unpleasant taste and odor in water. Iron bacteria do not pose a health risk, but they can make the water unsuitable for use and cause staining on fixtures and laundry.
Prevention through disinfection is the best way to keep your well and water system free of iron bacteria. The biofilm they form provide a protective environment for them, plus they have the ability to survive in low-nutrient, harsh environments. For these reasons, once iron bacteria have established in your well and water system, it can be very difficult and expensive to get rid of them.
What effects do iron bacteria have on well water?
Biofilm accumulation: While they do not impact human health, iron bacteria can be a major nuisance. They can create a slimy biofilm that can accumulate in your plumbing, well, and water treatment systems, which can lead to clogging and a reduction in water flow.
Staining of fixtures and laundry
Taste and Odor: Musty, earth odor and bitter, foul taste.
When should I test for iron bacteria?
If you notice a buildup of slime, staining on your fixtures, or odors from your water, it is recommended to have your water tested for bacteria and take appropriate measures to address the issue if the test comes back positive.
How should I treat for iron bacteria?
Once you test and have decided to treat your water for iron bacteria, the Minnesota Department of Health has developed a Home Water Treatment Guide that covers treatment for any common constituent in well water. The most important advice we can provide you is if you are going to add treatment to your home water system, be sure the treatment device has been certified to remove iron bacteria by an independent third-party certification organization.
Where can I get local help and information about iron in my well water?
Contact your local health department – They can help you interpret your sample results and may have information on the best treatment options for your situation. If they personally aren’t able to answer your questions, they will know who to contact who will be able to help you, likely at your state health department.
Contact a water treatment professional - we would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
State or Federal Geologic or Water Resource Agency – they may have completed field studies of your area or collected samples from water wells to map and understand the water quality in your state. In addition, they may house water well logs, including yours, or be able to provide additional information about the aquifer your well is getting water from.
Consult your well driller or drilling contractor – the contractor that drilled your well, and other local contractors, may be aware of the water quality issues nearby including high iron, and might have worked with other well owners in your area to solve this issue .
Research online – you should be inquisitive; it will help you significantly because there may be great information available online. Use search terms like “my state (CA, ME, IL, etc.) water well logs”, “my state groundwater quality”, or “my state well water quality”.
Contact us directly – if these other local sources don’t work out for you, we may be able to help. We may be able to provide direct assistance, and/or direct you to a technical assistance provider in your area who can help answer your questions (free service funded by USEPA).
Additional Resources
Well Management Section. Iron Bacteria in Well Water. 2019. Minnesota Department of Health.
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