Arsenic in groundwater naturally occurs in some areas of Michigan, and if you own a well in Marquette County or any place in the Upper Peninsula without a main water supply, there's always that chance some might slip into your drinking water.
Danger of arsenic contamination in the water has not been a risk historically in the Upper Peninsula. As a result, areas like Marquette County have not conducted many tests for it in wells. But when they do, they sometimes find a few wells that may be at risk.
"There's been very little testing, actually, in the State of Michigan and particularly in the U.P.," says Patrick Jacuzzo of the Marquette County Health Department. "It's not a known major issue in the U.P. However, there are some wells that have tested above recommended health limits in the western part of the county."
The Environmental Protection Agency says the maximum contamination limit for arsenic in drinking water is 10 parts per billion, or 0.1 milligrams per liter.
If you test your water and find higher levels, treat your water as soon as possible.