Manganese Water Test

Who should test for manganese

The U.S. Geological Survey found manganese above EPA's secondary standard in 21 percent^[6] of the domestic wells it sampled, in nearly all of the principal aquifers it studied. USGS says manganese is mobilized under certain conditions in the ground, such as low dissolved oxygen and low pH.

Test if a baby drinks the water. The Minnesota Department of Health (MDH) says you may want to test your drinking water for manganese, especially if infants drink your tap water. It says children and adults who drink water with high levels of manganese for a long time may have problems with memory, attention and motor skills, and that infants may develop learning and behavior problems. EPA's health advisory for manganese singles out infants younger than six months, as the what-your-level-means section below explains.

If you have a private well, nobody else tests it. MDH says some groundwater naturally has high levels of manganese and that you are responsible for testing your well as needed. Manganese is not part of the yearly well check CDC recommends (total coliform bacteria, nitrates, total dissolved solids and pH), so you have to ask for it.

If you are on public water, ask your water system first. MDH says public water systems may test their water for manganese, but they are not required to. EPA says public systems test for contaminants with secondary standards only on a voluntary basis. If your system has no result, you can order your own test from an accredited lab.

Test when you see the signs. Penn State Extension says that if you notice black stains or a metallic taste, you should arrange to have your water tested. MDH describes brownish-black or black stains on toilets, showers, tubs and sinks, and stained laundry. Staining is a nuisance sign; the health questions depend on the measured level.

To see manganese alongside the other tests your home needs, you can build a test plan, or read our well water testing guide for the yearly well check.

Certified lab or home kit

A certified lab gives you a number. MDH says the only way to know the level of manganese in your drinking water is to have it tested, and that all water testing should be done through an accredited laboratory. Contact a lab to get a sample container and instructions. CDC tells well owners that local or state health departments should have a list of state-certified laboratories. Our directory of certified water testing labs lists state-certified labs in the states we cover, and our guide to well water testing cost shows verified lab prices.

Why the number matters here. Manganese has two EPA benchmarks that do different jobs: a secondary standard for staining and taste, and a higher health advisory. A result is only useful if you can tell which side of each one your water is on, and that takes a measured concentration from a lab.

Ask for iron too. Penn State Extension says iron and manganese often occur together in groundwater, and that manganese usually occurs in much lower concentrations than iron. It also says the concentration and the form of each metal decide which treatment is practical. If you see orange-brown stains as well as black ones, add an iron water test to the same order.

A home kit gives you a rough read. A strip or color chart you read yourself is not a measured concentration from a certified lab, and you can't compare it with EPA's health advisory in the same way. Choose a certified lab when:

• A baby or young child drinks the water, or will soon.
• You want a number to compare with EPA's secondary standard and health advisory.
• You are deciding whether to spend money on treatment, or checking whether treatment works.
• A home kit showed manganese, and you want to know how much.

Lab methods

• EPA 200.7
• EPA 200.8
• EPA 200.9
• SM 3120 B
• SM 3111 B
• SM 3113 B

Source: ecfr.gov (source for lab methods) (opens in a new tab)

How to collect a manganese sample

Follow the instructions in your lab's kit first, since they are written for that lab's bottle and method. The quick guide near the top of this page lists the sample bottle and the preservative for manganese, and the methods labs use are listed under "Certified lab or home kit" above. The steps below explain what most kits ask you to do and why.

1. Decide what you want to know. If you have a softener or other treatment, ask the lab whether to sample before it, after it, or both. MDH notes that certain home treatment units may make the manganese level in your tap water lower than what your water system detected, so a sample after treatment tells you what you are drinking, and one before it tells you about the source water.
2. Pick the right tap. Use a cold-water tap you drink or cook from, usually the kitchen sink, unless your lab names another one. If a baby's formula is made with water from a particular tap, that is a good one to test.
3. Remove any attachments. Take off a hose or aerator attachment, unless your kit says otherwise.
4. Run the water the way your lab says. Your kit tells you whether to let the water run before you fill the bottle, and for how long.
5. Fill the bottle without rinsing it. The quick guide shows that manganese samples are preserved with acid. If the bottle came with anything inside, don't rinse it out, and don't let it overflow. Cap it tightly.
6. Label and record. Write the date, time and tap, and whether the sample was taken before or after any treatment.
7. Send it on time. Pack the sample the way your lab asks and send it within the window it gives you.

Common mistakes to avoid

• Sampling only after a softener when you wanted to know about the well itself.
• Rinsing out a bottle that came with a preservative inside.
• Sampling from an outdoor spigot or a hose when you wanted to know about your drinking water.
• Leaving manganese off the test when infants drink your tap water, the case MDH singles out.

What your manganese level means

Your lab report gives a number. Compare it with both EPA benchmarks, because they answer different questions.

The secondary standard is 0.05 mg/L^[2]. It is a non-enforceable guideline for color, staining and taste. EPA lists black to brown color, black staining and a bitter metallic taste as the effects above it. EPA's health advisory recommends reducing manganese to or below this level for consumer acceptance.

The lifetime health advisory is 0.3 mg/L^[1]. EPA says it will protect against concerns of potential neurological effects. It is a non-enforceable guideline, not a legal limit; manganese has no federal MCL.

Infants younger than six months. EPA's health advisory gives a higher value for short exposures of up to ten days, but advises that for infants younger than six months the lifetime value be used even for a ten-day exposure. EPA gives its reasons as differences in manganese content between human milk and formula, and the possibility that young infants absorb more and excrete less.

A water test can't diagnose anything. If you have health concerns, or a baby has been drinking the water, talk to a health professional and bring your lab report. Our guide to manganese in water covers the health effects, where manganese comes from and what to do after a confirmed result.

Putting your result in context

• No manganese detected. No treatment needed based on this result. Keep the report so you can compare future tests.
• Below the secondary standard. No treatment needed based on this result. Staining and taste problems are unlikely.
• Between the secondary standard and the health advisory. The water may stain and taste metallic. MDH sets its own guidance for homes where an infant drinks tap water or formula made with it, and that guidance is lower than EPA's health advisory, so if a baby drinks the water, ask your local health department what it advises.
• At or above the health advisory. Retest with a certified lab to confirm. If an infant drinks the water, talk to your local health department and a health professional about what the baby should drink in the meantime.

MDH says drinking water with high manganese can be harmful, but bathing or showering in it is not. Any treatment choice should start from a confirmed certified-lab result, and a retest of the treated water shows whether it worked.