Iron is one of the most common contaminants in well water, and it’s responsible for both unsightly orange stains and even appliance damage when left untreated.
Fortunately, there are steps you can take to remove each different form of iron from your water supply so that you can enjoy clean, healthy, and safe water for your whole home.
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How Does Iron Get Into Well Water?
Iron is the fourth most abundant element in the Earth’s crust by mass. It’s also thought to make up a large portion of the Earth’s core, and serves several key functions in nature including helping mammals carry oxygen in their blood and aiding plant growth.
Even when not present as hematite or magnetite, the two most common forms of iron ore, iron is so prevalent in the ground that any water that comes from ground sources is likely to contain iron. Heavy rainfall or snow can exacerbate this contamination by dissolving iron deposits as it seeps into the ground and bringing them to the well water source.
The other way iron gets into your well water is by corroded iron pipes. Iron corrodes, or wears away, when it comes into contact with air or water. This causes the iron to become oxidized, which turns it into rust. As the pipes start corroding those rust flakes are then released into the water, which will turn it brown or orange in large enough quantities.
How Iron in Water Damages Your Appliances
Even at concentrations as low as 3ppm (parts per million) which is the EPA recommended limit for iron in water, iron can be problematic. It’s ability to cause damage and unsightly stains at such low concentrations is part of what makes it such a source of exasperation for many homeowners with well water.
Often the most noticeable sign of iron being present in your water is the orange staining it leaves on everything – from streaks in your toilet bowl to trails and discoloration in your sinks, showers, and bathtubs. What many people may not realize is that the staining doesn’t stop there. With repeated washes your laundry and dishes can even become stained, and so can your hair.
Showering with excessive iron in the water can cause your hair to become dull and brittle, and you can taste the difference in your water as well. Iron imparts an unpleasant, metallic taste that is reminiscent of blood, and even the odor of your water will be affected.
Anything you make with the contaminated water including coffee and tea will carry that metallic taste, but iron is considered a secondary contaminant by the EPA – one that has mainly aesthetic impacts but isn’t harmful to consume. It would take an extremely high level of iron to cause any detrimental health effects or signs of toxicity, but your appliances unfortunately aren’t so lucky.
Even at low levels iron residues can collect in your pipes and appliances and cause restricted water flow. This means decreased water pressure to your shower head, your dishwasher, your water heater, etc and can even cause them to malfunction when it builds up enough. You don’t want to have to repair or replace your appliances any sooner than you must.
Signs That You Have an Iron Problem
As mentioned, orange staining on your sinks, toilets, and other fixtures is one of the most sure-fire signs that you have iron in your water. If your water has a strange metallic taste and a harsh odor, that’s another big sign.
In some severe cases, your water may even come out yellow, orange, or brown from the tap.
Not all iron contamination is so obvious, however. One form of iron is completely clear, so you would never know just by looking at the water that there was any iron in it.
You can purchase a water test kit that will tell you exactly how much iron is present in your water as well as the levels of many other contaminants. This will help you choose the best strategy for removing that iron, and you can see our top recommendations for test kits here.
The Four Types of Iron Found in Well Water
Iron comes in four main forms and each behaves differently in your water supply. We’ll cover what they look like, as well as how to remove each one.
1. Ferric Iron
Ferric iron, also commonly called rust, is the form iron takes when it has been oxidized. This means that each iron particle has lost one of its electrons, and ferric iron is not soluble in water.
The rust particles precipitate out and can be most easily captured and removed by sediment filters.
2. Ferrous Iron
Where ferric iron is insoluble, ferrous iron is the water-soluble version of iron that remains dissolved. This doesn’t mean that it won’t still cause damage and staining, however, but you wouldn’t know it was in your water just by looking at it.
This form of iron requires filters like KDF media or AIO systems to be properly removed – both of which oxidize ferrous iron into its ferric form.
3. Colloidal Iron
Colloidal iron is the same type chemically as ferric iron, but with much smaller particles.
Sediment filters will commonly work on particles down to 5 microns in size, yet colloidal iron can be present with particles as small as 0.01 microns.
This form of iron is much less common than regular ferric iron, and requires specialized microfiltration in order to completely remove it.
For most households, however, removing it isn’t a necessity as long as you’re below the 3ppm threshold.
4. Bacterial Iron
What’s worse than iron in your water? Iron and bacteria together. Certain species of bacteria oxidize ferrous iron and turn it into ferric iron, which provides them with energy in return. These bacteria then form sticky patches of slime, rust, and bacterial colonies that cement themselves to the insides of your plumbing fixtures – including your pipes and pumps.
This iron and the bacterial matrix holding it requires chemical treatment like disinfection with chlorine, or pasteurization by injecting steam or hot water into the well in order to properly remove them.
Fortunately, this is one of the less common forms of iron contamination in wells.
Iron is a nuisance to have in your well, but since it’s one of the most abundant elements in the Earth’s crust you’re bound to run into it no matter where you live.
Iron is responsible for orange staining, poor fixture and appliance performance, and even damaged hair when not treated in your water supply.
Now that you know a little more about iron and how you can remove it from your well water be sure to check out our specific iron filter review guide for product recommendations.