BISMARCK, N.D. – The North Dakota Department of Environmental Quality (NDDEQ) is providing information about the health effects of manganese in drinking water. Manganese is an abundant metal that occurs naturally in rocks, soil, groundwater and surface water. North Dakota has naturally occurring manganese in water.
People need some manganese to stay healthy, but too much can be harmful. Children and adults who drink water with high levels for a long time may have problems with memory, attention and motor skills. Infants under six months of age may develop learning and behavior problems if they drink water with too much manganese.
To keep household drinking water safe, the NDDEQ recommends the following:
• Per U.S. Environmental Protection Agency (EPA) guidance, drinking water should not contain more than 0.3 milligrams per liter (mg/L).
• For infants (under six months of age), tap water with manganese levels above 0.3 mg/L should not be used for drinking or making formula.
Bathing or showering, washing dishes or clothing with water containing manganese levels above guidance levels is not harmful if the water is not ingested.
Recent studies have focused increased attention on manganese in drinking water; however, the EPA has not established a National Primary Drinking Water Regulation for manganese. Because EPA has not established a regulation, public water systems are not required to meet the guidance values, and some may not. Some systems may test for manganese but are not required to do so.
The NDDEQ is working with public water systems that have elevated manganese levels, and these systems will be notifying their consumers.
Individuals served by a community public water system can get test results for manganese, along with other water quality information, from their system’s Consumer Confidence Report.
Some non-community public water systems such as campgrounds or rest areas with their own wells may monitor for manganese, but others do not and are not required to do so. Information on manganese in these systems may not be available.
Private well owners are encouraged to test their drinking water for manganese, especially if infants in the household drink tap water or formula made with tap water.
Certain household water treatment units may reduce the level of manganese in drinking water, but the only way to know the level is to have the water tested by an accredited laboratory. For more information on water testing, manganese in drinking water and effective household treatment units, contact the department’s Drinking Water Program at 701-328-5211, or visit deq.nd.gov.