Iron in Drinking Water

Consuming water containing iron is not harmful to your health. High levels of iron may cause: 

• A metallic taste
• A bad smell
• Rusty-colored water
• Mineral deposits on toilets, sinks and bathtubs
• Sedimentation (for example, small particles of iron settling at the bottom of a water glass)
• Reddish or orange staining on laundry or surfaces that come in contact with the water

None of these effects poses a health risk.

High levels of iron may also allow the growth of iron bacteria, which produce a slime that can clog filters and plumbing. Although these bacteria can make water taste or smell bad, there do not harm your health.

Iron is a metal found naturally in the Earth’s crust. As rainwater moves through natural rock formations underground, it can dissolve iron and carry it into aquifers that serve as sources of drinking water. 

Testing for iron is the only way to know if it is the cause of an issue. Other naturally occurring elements, such as manganese, can cause similar color and taste issues and could be harmful if not fixed. 

The Health Department recommends testing your private water source for iron (and manganese) every five years. You can order an inorganic chemical test (Kit C) from the Health Department Laboratory, or you can use another certified drinking water lab to test for inorganic chemicals.

The drinking water standard for iron is 0.30 mg/L (milligrams per liter). It is called a secondary maximum contaminant level, or SMCL, because the level is based on aesthetic (color and taste) reasons rather than health effects. 

If the iron level in your water is at or above 0.30 mg/L, there may be: 

• A metallic taste
• A bad smell
• Rusty-colored water
• Mineral deposits on toilets, sinks and bathtubs
• Sedimentation (for example, small particles of iron settling at the bottom of a water glass)
• Reddish or orange staining on laundry or surfaces that come in contact with the water

None of these pose a health risk. You may consider treatment to improve the taste and appearance of your water. 

Need help understanding your drinking water test results? Find out how to read your results

When treating for iron in drinking water, it is important to consider whether there are other contaminants that should be removed, such as manganese, which causes similar aesthetic (color or taste) problems. Additionally, some things – like the pH, hardness and amount of iron in the water – may impact how effective a treatment system is. A water treatment professional will be able to determine which treatment system is best for your water, but in most cases, iron levels can be lowered by using one or more of the following treatment systems listed below. 

If fixture staining is a concern throughout the home, a whole house system (point-of-entry or POE) is recommended, which includes:

• Water softener (cation exchange) with an NSF/ANSI Standard 44 Certification
• Oxidizing filter system that uses air as the oxidizing agent with an NSF/ANSI Standard 42 Certification

In some cases, for large particulate iron or fine iron sediments, a 5 or 20 micron sediment filter may fix the problem.

If you would like to treat just the water you drink or cook with, you may consider installing a point-of-use (POU) system, which include:

• Oxidizing filter: a pitcher-style or under-sink filter with an NSF/ANSI Standard 42 Certification
• Reverse osmosis: an under-sink system with an NSF/ANSI Standard 58 Certification

Re-test your drinking water for iron after any treatment system is installed to make sure levels are below the drinking water standard.

Funding is available to help you pay for water treatment or to fix your water system. Learn more about financial assistance programs and eligibility.