Manganese in Well Water: Black Stains and Safe Levels

Manganese in well water is a natural mineral that leaves black or brown-black stains. It starts staining at about 0.05 mg/L. The EPA's health advisory is higher, at 0.3 mg/L. Below that, it's mostly a nuisance. Above it, stop using the water for baby formula and get it treated. A lab test tells you which side you're on.

What does manganese in well water look like?

It looks like black stains that keep coming back. Check the toilet tank first. Then look at the dishwasher, the shower floor and your white laundry.

The water itself usually runs clear. That fools people. Dissolved manganese only turns black after it meets air. So the glass looks fine and the tub doesn't.

It doesn't take much. Manganese can coat the inside of pipes at just 0.02 mg/L. Those coatings break loose later as black flecks. Is your water orange instead? That's iron, and our page on iron in well water covers it. The two often show up together.

Is water with manganese safe to drink?

At low levels, yes. Your body needs a little manganese, and most of it comes from food. The question is how much is in the water.

Two numbers matter here. The first is 0.05 mg/L, the EPA's guideline for staining and taste. It isn't a health limit. The second is 0.3 mg/L, the EPA's lifetime health advisory. That one was set to protect the nervous system.

Babies are the ones to watch. Infants under six months should stay under 0.3 mg/L, even for short periods. Formula mixed with high-manganese water is the concern. Got a baby in the house and black stains in the tub? Use bottled water for formula until a lab result comes back.

Why do South Carolina wells have manganese?

It comes out of the ground. Rock and soil hold manganese, and groundwater dissolves it on the way to your well. Nobody put it there.

Acidic water holds more of it. Dissolved manganese is most common in groundwater with a pH below 7. That matters here. The Coastal Plain aquifers under Aiken County and part of Lexington County run acidic.

A stain that shows up suddenly is a different story. It can mean sediment or a change in the well itself. Our page on sediment in well water helps sort that out.

How do you get rid of manganese in a well?

You treat the water after it leaves the well. Which system works depends on your test numbers. Guess wrong and you'll still be scrubbing the tub.

A water softener can handle small amounts. Higher levels call for an oxidizing filter, which turns dissolved manganese into particles and traps them. Greensand is the common one. It's generally recommended when iron and manganese together run 3 to 10 mg/L.

But pH decides whether the filter works. Manganese is harder to remove than iron. One common filter media needs a pH of 7.5 or higher to catch it. Acidic water slips right through. So the pH often has to be corrected first. Our guide to an iron filter for well water explains how that sizing works.

This is why Austin Drilling tests before recommending anything. Our mineral test checks iron, manganese, hardness and pH together. Then our water treatment crew matches the system to the numbers. And retest after it's installed. That's the only way to know it worked.

Fighting manganese in well water? Call Austin Drilling in West Columbia at (803) 926-5402 or Newberry at (803) 926-7080. We're open Monday through Friday, 7am to 6pm. We've been fixing South Carolina well water for 66 years.

FAQ

Do water softeners remove manganese from well water?

A softener removes small amounts. It struggles when levels climb or the pH runs low. Test first so you know whether a softener alone will do it.

Can you shower in water high in manganese?

Yes, you can. The concern with manganese is drinking it. Bathing and showering aren't the risk, though the stains on the tub are a nuisance.

What filter removes manganese in well water?

An oxidizing filter is the usual answer for higher levels. Greensand is a common type. The right one depends on your manganese level, your iron level and your pH.

How do I test for manganese in well water?

Stains mean it's there, but they don't give a number. Austin Drilling's mineral test does. Well water testing explains when you need a certified lab, and that's the result to trust for a baby's formula.