Manganese is an essential metal needed for the body to function. Small amounts of manganese are added to most vitamin supplements and baby formulas to make sure people get enough. Some common dietary sources of manganese are nuts, tea, leafy greens and whole grains. Your daily intake of manganese will depend on your food choices, and it includes the water you drink.
Manganese is also found in some rocks and soils in Vermont and can get into groundwater. Manganese can be a problem for well owners for two reasons:
- It can cause a bitter taste.
- It can cause black stains on plumbing fixtures and laundry.
Consuming too much manganese over a long period of time could harm your nervous system. Studies suggest that babies may be especially sensitive when fed formula made with well water that has high amounts of manganese.
The Health Department recommends testing your private water source for manganese every five years.
Levels of manganese in drinking water are regulated by the Environmental Protection Agency (EPA) and the State of Vermont. The Health Department has set an advisory level for manganese at the EPA’s lifetime health advisory of 0.300 mg/L (milligrams per liter) to protect the nervous system.
And as a general rule, manganese concentrations below 0.050 mg/L will not cause staining or a bitter taste.
The Health Department Laboratory offers test kits for manganese.
Manganese can be lowered or removed from drinking water with treatment.
Manganese is removed as the water flows through the filter.
This treatment that uses chlorine, air, or peroxide followed by a filter.
Cation Exchange Treatment
A conventional water softener (also called a cation exchange softener) exchanges manganese for sodium or potassium, which remains in the water. The manganese is flushed away with the wastewater when the softener is cleaned. This type of treatment is typically installed as a whole house system (point-of-entry).
Re-test for manganese after any treatment system is installed to make sure levels are below the advisory level.