What Causes Iron in Water and How Is It Treated?

Iron can enter water naturally from soil and rock or through corroding pipes and equipment. When the iron is still dissolved, the water may look clear as it leaves the faucet. After the water is exposed to air, the iron reacts with oxygen and forms rust-colored particles that can turn the water yellow, orange, or brown. If those particles are already visible when the water reaches the faucet, the iron has oxidized earlier in the water system.

Iron bacteria are a separate issue. These microorganisms use iron and can create slimy buildup, unpleasant odors, and recurring stains.

Treatment depends on the form and concentration of iron, along with pH, manganese, hardness, and bacterial activity. A softener may handle limited amounts of dissolved iron under suitable conditions. Higher levels commonly require oxidation followed by filtration, while iron bacteria may require well or plumbing disinfection. A water test and treatment plan prevent trial-and-error equipment purchases.