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How to Test Well Water for Iron: What to Ask For and How to Read Results

Iron testing seems straightforward until you realize there are multiple things to test for, and a basic total iron number doesn’t tell you which treatment to buy. Getting the right tests up front saves you from spending money on a system that doesn’t match your actual problem.

What Tests to Order

Ask for these parameters specifically when calling a lab. Don’t just say “test for iron” and assume they’ll run everything you need.

Total iron gives you the big picture number, measured in milligrams per liter (mg/L). This is the sum of all iron forms present. It’s the number you’ll compare against the EPA secondary standard.

Dissolved iron tells you how much of your total iron is in the ferrous (dissolved) form vs. ferric (particulate) form. Labs run this by filtering the sample before analysis. The difference between total iron and filtered iron tells you how much is particulate. This split is important for choosing between oxidizing filters and sediment filters.

Iron speciation (ferrous vs. ferric) is the more detailed version of the above. Some labs report it this way explicitly. If your lab offers it, ask for it.

Iron bacteria is a separate biological test entirely. It doesn’t show up on a chemistry panel. You’re looking for living organisms, not dissolved minerals. Many state labs and mail-in services offer an iron bacteria test as an add-on to their standard well panels. If you have slime in your toilet tank, stringy orange deposits in your pipes, or an oily or swampy odor alongside orange color, order this test alongside your chemistry panel.

Manganese is worth testing at the same time. Iron and manganese often occur together in well water, and treatment systems for iron frequently also address manganese. Knowing your manganese level before you buy a filter avoids a second round of testing after installation.

How to Find a Certified Lab

Your state health department is the best starting point. Most states maintain a list of certified drinking water labs, and some state labs run the tests themselves at low or no cost for private well owners. Search your state’s name plus “certified drinking water lab” or call your county health department.

Mail-in services are the other option, especially if your state doesn’t offer affordable lab testing directly. Mail-in water test services vary in what their panels include, so check the parameter list before ordering. Look for labs certified under your state’s program or under the EPA’s National Environmental Laboratory Accreditation Program (NELAP).

When you call a lab, tell them you’re testing a private well for iron problems. Ask specifically:

  • Does your well panel include total iron and dissolved iron separately?
  • Do you offer iron speciation (ferrous vs. ferric)?
  • Do you offer an iron bacteria biological test as an add-on?
  • What’s your turnaround time, and do you include manganese in the standard panel?

A good lab will answer these questions clearly. If they can’t tell you what parameters are included, find a different lab.

How to Collect the Sample Correctly

Sample collection affects your results more than most people expect. Running your tap for different amounts of time before sampling gives you completely different readings, and both have legitimate uses.

A first-draw sample means you collect water without flushing the tap first. You fill the bottle from the very first water that comes out of the faucet. This gives you a worst-case reading, because it includes water that’s been sitting in contact with your pipes and fixtures. For iron, this is often more relevant to what you’re actually experiencing day-to-day.

A flushed sample means you run the tap for 2 full minutes before collecting. This pulls water directly from the well and represents what your source water looks like before it contacts your plumbing. If you want to understand what the well itself is producing, flush first.

For iron problems specifically, testing both can be useful. If your flushed sample shows much less iron than your first-draw sample, some of your iron may be coming from corroding pipes, not just the well. If both samples are similarly high, the source is the well itself.

Follow your lab’s specific collection instructions. They’ll specify the bottle type (usually a plastic bottle for iron), any preservatives needed, and whether samples should be chilled during shipping.

Reading Your Results

The EPA Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 mg/L. Secondary standards are not health-based. They’re aesthetic standards. There’s no federal health limit for iron at concentrations typically found in wells. But 0.3 mg/L is the practical threshold where problems appear.

Below 0.3 mg/L: most people don’t notice anything. Staining is rare. Taste is usually fine.

0.3 to 1 mg/L: you’ll likely see occasional staining in sinks, toilets, and laundry. Taste and odor may be noticeable. Treatment is worth considering.

Above 1 mg/L: staining is persistent and severe. Laundry turns orange. Fixture staining requires regular cleaning. Treatment is recommended.

Above 3-5 mg/L: significant staining in all fixtures, strong metallic taste, potential for pipe buildup and clogging. Treatment is necessary.

Look at the ferrous vs. ferric split in your results. If most of your total iron is ferrous (dissolved), you need an oxidizing filter. If most is ferric (particulate), a quality sediment filter may be sufficient. Many wells have both, and treatment systems often address both in sequence.

Using Results to Choose Treatment

Once you have your numbers, match them to the right treatment approach. The iron bacteria vs. dissolved iron page explains how the three iron types call for different solutions. The iron contaminant hub has a full treatment overview.

If you’re ready to look at specific systems, how to remove iron from well water walks through the decision by iron type and level. The best iron filters for well water compares systems across different iron profiles and budgets.

Don’t skip the testing step and guess based on staining alone. Orange staining has multiple causes, and the most effective treatment depends on your actual numbers.

Sources

Frequently Asked Questions

What level of iron in well water requires treatment?
The EPA Secondary MCL for iron is 0.3 mg/L. At that level, iron causes staining on fixtures and laundry and an unpleasant metallic taste. There's no health-based MCL for iron at typical well water concentrations. But 0.3 mg/L is the practical threshold where most people start experiencing problems with staining and taste. Many wells in iron-rich regions run 2-5 mg/L or higher, where the staining and taste issues are severe.
Does a standard water test include iron?
Many full well water panels include total iron, but not all. When ordering a test, ask specifically for total iron, dissolved iron, and ferrous vs. ferric iron speciation if your lab offers it. Some mail-in panels include iron bacteria testing as a separate add-on. Check the list of parameters before ordering.
Can I use a home iron test kit?
Yes, home iron test kits exist and work reasonably well for basic screening. They typically use a colorimetric test that changes color based on iron concentration. They're accurate enough to confirm whether iron is present and roughly how high the level is. But they won't distinguish between ferrous and ferric iron, and they won't detect iron bacteria. A certified lab test is more reliable if you need a precise number for treatment sizing.
Should I test before or after my water softener?
Both. Test your untreated source water to understand what you're dealing with. Test the softener output to see if the system is affecting iron levels. Water softeners can remove ferrous iron to some extent through ion exchange but aren't designed as iron filters and won't address ferric iron or iron bacteria. Knowing both sides of the softener gives you a complete picture.
How often should I test my well for iron?
If you have a known iron problem and a treatment system installed, test your raw water once a year and your treated water every 1-2 years. Iron levels in wells can shift seasonally or after heavy rainfall. If you notice new staining or taste changes, test regardless of schedule.