Iron and Manganese in Well Water

Iron and manganese are naturally occurring elements found in rocks, soil, and sediments. As groundwater moves through these materials, it can dissolve small amounts. In private wells, iron and manganese often appear together because they respond to similar underground conditions. (USGS)

They can appear in different forms:

• Dissolved (clear-water): Water looks clear at the tap but turns yellow, orange, or black after sitting
• Particulate: Visible rust or sediment comes out immediately

The form matters for treatment selection, but for most homeowners, the symptoms tell you enough to get started with testing.

Iron: Mostly a Nuisance

At levels found in most wells, iron is not a health concern. It is included in EPA's secondary standards, which address taste, odor, and staining rather than health. (EPA)

Iron can still be a significant annoyance. It causes orange stains, metallic taste, and can damage appliances over time.

Manganese: Nuisance at Low Levels, More Concern at High Levels

Manganese also has an EPA secondary standard for aesthetics (0.05 mg/L). At modest levels above this, the main issues are black staining and taste.

However, manganese has also been studied for potential neurological effects at higher exposures. The EPA has a drinking water health advisory with a lifetime level of 0.3 mg/L (300 µg/L), with extra caution for infants under 6 months. (EPA)

Several state health agencies advise that infants should not drink water above 0.3 mg/L manganese. (ME CDC)

Iron and manganese are more likely to dissolve into groundwater under low-oxygen conditions. Many aquifers, especially deeper or confined zones, naturally have low oxygen, making them prone to elevated iron and manganese.

Levels can vary widely even between nearby wells because of differences in:

• Well depth and screened interval
• The specific geologic layer tapped
• Groundwater chemistry and oxygen levels

Your neighbor's results do not predict yours.

Discoloration

• Iron: Yellow, orange, or brown water
• Manganese: Brown to black discoloration

Staining

• Orange or rust stains in sinks, tubs, and toilets (iron)
• Black stains on fixtures and laundry (manganese)
• Spots on dishes and cloudy glassware

Taste and Odor

• Metallic taste
• Bitter notes (more common with manganese)

Plumbing Buildup

Over time, iron and manganese can build up in pipes, water heaters, and appliances. This can reduce flow, clog fixtures, and shorten appliance life. (USGS)

Test if you notice:

• Rusty, brown, or black water
• Staining on fixtures, laundry, or dishes
• Metallic or bitter taste
• Frequent clogging of aerators or showerheads
• Sediment or buildup in appliances

Even without symptoms, testing is worthwhile if neighbors have iron or manganese issues, or if you want a baseline for your well.

Iron and manganese are usually included in general chemistry or metals panels from certified labs.

Sample Collection

Unlike bacteria tests, iron and manganese samples are not as time-sensitive. Follow the lab's instructions for bottle type and any preservatives needed.

Total vs Dissolved

Some labs report both total and dissolved iron/manganese. If you are planning treatment, ask whether this information would help select the right system.

Cost and Turnaround

Iron and manganese are typically included in basic well panels costing $50 to $100. Results come back within 1 to 2 weeks.

Reference Levels

EPA Secondary Standards (for aesthetics, not health): (EPA)

• Iron: 0.3 mg/L
• Manganese: 0.05 mg/L

EPA Manganese Health Advisory (lifetime): (EPA)

• 0.3 mg/L (300 µg/L)

What Your Numbers Mean

Iron above 0.3 mg/L: Expect staining and taste issues. Treatment is optional but often worthwhile for quality of life.

Manganese 0.05 to 0.3 mg/L: Staining and taste are likely. Treatment is optional for adults but consider it if infants use the water.

Manganese above 0.3 mg/L: Take extra caution if infants are in the home. Consider treatment or an alternative drinking water source. (ME CDC)

When Treatment Is Optional

• Mild staining or taste you can tolerate
• Iron/manganese only slightly above secondary standards
• No infants in the home

When Treatment Is Recommended

• Severe staining or appliance damage
• Manganese above 0.3 mg/L, especially with infants
• Persistent plumbing clogs or buildup

Treatment Options

The right system depends on your water chemistry and the form of iron/manganese. Common approaches include:

• Oxidation and filtration: Oxidizes dissolved minerals into particles, then filters them out
• Specialized media filters: Target iron and manganese specifically
• Water softeners: Can help with some forms of iron, but not a universal solution
• Point-of-use systems: For drinking water only, when whole-house treatment is not needed

After installing treatment, retest to verify performance. These systems need regular maintenance.

While you evaluate treatment options, these steps can help:

• Clean faucet aerators regularly to reduce buildup
• Flush pipes after long periods of non-use
• Avoid washing whites during peak discoloration
• Use cold water for drinking if hot water shows more discoloration (water heaters accumulate sediment)

Most certified labs include iron and manganese in basic well water panels. If you are planning treatment, ask whether they can distinguish between dissolved and particulate forms.

Find well water testing providers in your state using our directory.