Manganese in Well Water: Stains, Taste and Infant Health
What it is
Manganese is a natural metal in soil and rock that dissolves into groundwater, often with iron. It causes black or brown stains and a bitter taste.
Limits
EPA's secondary (aesthetic) limit is 0.05 mg/L. Health Canada sets a health-based maximum of 0.12 mg/L and an aesthetic objective of 0.02 mg/L, noting that infants are most sensitive.
What to do
Above the health-based level, don't use the water for infant formula. Treatment usually means oxidation and filtration, or a softener for low levels. Penn State Extension explains the options.
Sources
- EPA: Secondary drinking water standards
- Health Canada: Guidelines for Canadian Drinking Water Quality, summary table
- Penn State Extension: Iron and manganese in private water systems
Questions
Is manganese in well water harmful?
At low levels it's mainly a staining and taste issue. At higher levels it's a health concern, especially for infants. Health Canada's maximum is 0.12 mg/L.
Free well water safety checklist
15 family-friendly steps based on CDC and EPA guidance. Print it, keep it on the fridge, and know when to call a certified lab.
More guides
- Flood Protection for Well Owners: Before, During and After a FloodRaise and seal the wellhead, know your pump shutoff, then disinfect and test with a certified lab after any flood.
- PFAS “Forever Chemicals” in Private Wells: Why You Should TestFederal PFAS rules protect public water systems — not private wells. Here’s what “forever chemicals” mean for well owners and how to get tested.
- Nitrates in Well Water and Blue Baby Syndrome: Who Must TestNitrate in well water can cause blue baby syndrome in infants. Learn who is at risk, when to test, and how to find a certified lab.
- Arsenic in Private Well Water: The Invisible Risk UndergroundArsenic in groundwater is often naturally occurring and invisible. USGS research shows millions of private-well users may be above the EPA drinking-water standard.