Ground water and geology of Marquette County, Michigan

Ground-water resources of Marquette County are about evenly divided between bedrock aquifers and aquifers in glacial deposits. In the northern and the extreme southern parts of the county, most wells are completed in bedrock at depths less than 100 feet. In the central part, most wells are completed in glacial deposits; some of these wells are as deep as 200 feet. Yields, in some places as high as 300 gallons per minute, are generally greatest from wells completed in glacial deposits. Most well water is hard and has iron concentrations ranging from <0.1 mg/L to about 5.0 mg/L. Both ground water and surface water sources are used in municipal water systems.