The Michigan Department of Environment, Great Lakes, and Energy (EGLE) recently kicked off a Statewide Manganese Occurrence Study that will focus on sampling water in 41 Michigan counties. The goal is to identify areas at risk of elevated manganese levels and provide insights into mitigation strategies.

What is it?

Manganese is a naturally occurring chemical element found across the Earth in rocks, soil, water, and even some foods. While it is an essential nutrient to both humans and animals, high levels of manganese can be toxic, which is why it is more recently being investigated as a contaminant of concern.

Its presence in water appears as black flecks or causes the water itself to be tinted black/dark brown.

Where is it?

Manganese in drinking water is found primarily as a naturally occurring mineral in formations rich in iron and other metallic ores. For example, in the Upper Peninsula, the Banded Iron Formation, BIF, is rich in iron and other metals, thus a concern for manganese water contamination.

What is being done?

Recent research has highlighted potential health risks associated with elevated manganese levels, leading to its classification as a contaminant of emerging concern.

Studies have shown that prolonged exposure to high levels of manganese can have adverse effects on human health, particularly impacting cognitive and neurological functions, especially in children. Other effects are muscle weakness, lethargy, deficits in memory and motor skills, and damage to reproduction and the nervous system.

As a result, regulatory agencies and environmental organizations are increasingly focusing on monitoring and mitigating manganese levels in drinking water to safeguard public health beyond aesthetic considerations.

Currently, there is no regulatory mandate for public water supplies to routinely test for manganese. However, the EGLE is addressing this concern through initiatives like the Statewide Manganese Occurrence Study (SEECS).

 This study, which recently began, will focus on sampling water from 41 counties, encompassing 600 community water supply systems and 400 non-community systems across Michigan.

Another upcoming initiative is the Emerging Contaminants in Small and Disadvantaged Communities (EC-SDC) grant. This program is designed to support communities in identifying and addressing emerging contaminants in drinking water sources. The two areas of focus in the state of Michigan are Gogebic County and Marquette County, both in the Upper Peninsula.

Manganese is part of EGLE’s new Contaminants of Emerging Concern collection of webpages.

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