Manganese in drinking water
Also called Mn.
- Legal limit
- None
- Health goal
- None
- Federal benchmark
- EPA lifetime health advisory (2004), not enforceable: 300 ppb
Values in parts per billion (ppb). Comes from the source.
Contaminant referenceLimits checked Oct. 4, 2026
Where the rules stand
No federal MCL. EPA's non-enforceable secondary standard is 50 ppb (0.05 mg/L), for color, staining and taste. EPA's 2004 lifetime health advisory is 300 ppb, and its 1-day and 10-day advisory is 1,000 ppb. For infants under six months, EPA advises using 300 ppb even for 10-day exposure. NSF lists manganese as an NSF/ANSI 42 claim, but neither NSF nor WQA listings showed a product with it on Oct. 4, 2026.
Where to find your level
EPA’s national data doesn’t carry manganese results for utilities. Your utility’s annual water quality report may list it; on a private well, a lab test will.
What EPA says about health
EPA says its 300 ppb lifetime advisory protects against possible nervous system effects. Manganese is also an essential nutrient. Above 50 ppb, water may turn black or brown, stain fixtures and taste bitter.
Where it comes from
Manganese occurs naturally in many surface water and groundwater sources and in soils, according to EPA.
What handles it
- NSF/ANSI 42
Claim to look for: Manganese
NSF lists manganese as a possible NSF/ANSI 42 claim, but neither NSF nor WQA listings showed a product with it on Oct. 4, 2026. WQA has no manganese claim.
Sources
- Secondary Drinking Water Standards: Guidance for Nuisance Chemicals, U.S. EPA. Checked Oct. 4, 2026.
- Drinking Water Health Advisory for Manganese (EPA-822-R-04-003, January 2004), U.S. EPA. Checked Oct. 4, 2026.
- NSF/ANSI 42, 53 and 401: Filtration Systems Standards, NSF. Checked Oct. 4, 2026.
- Search for NSF Certified Drinking Water Treatment Units (standards and reduction claims lists), NSF. Checked Oct. 4, 2026.
- Find WQA Certified Products (Gold Seal listings by standard and claim), Water Quality Association. Checked Oct. 4, 2026.