Marquette Water Hardness & Quality Report (2026)

The City of Marquette and Charter Township of Marquette jointly operate the Marquette Water Filtration Plant, sourcing all drinking water exclusively from Lake Superior via an intake on Lakeshore Boulevard at Ridge Street. This surface water is treated using a state-of-the-art microfiltration membrane system before distribution. The utility serves Marquette County residents across the city of Marquette and nearby townships, having provided high-quality drinking water for over 141 years, with no groundwater or mixed sources used at any point in the supply chain.

The Lake Superior watershed spans the Upper Great Lakes region, with source water drawn from this massive oligotrophic lake formed by glacial carving over Precambrian bedrock. The geology features resistant Canadian Shield rocks — Archean granites, volcanics, and greenstone belts — with thin Quaternary glacial till and sand deposits. This low-carbonate environment yields naturally very soft water with minimal mineral content, though municipal treatment may introduce slight mineralization, shaping a moderately mineralised supply overall.

Moderately hard water from Marquette promotes moderate scale buildup in water heaters, dishwashers, and coffee makers, reducing efficiency over time and increasing energy costs. Soap lathering is somewhat reduced, leading to higher detergent use in laundry. Regular maintenance — such as annual descaling of fixtures and heaters — helps mitigate issues. A water softener is optional but recommended for households noticing spotting on glassware or dry skin from showers. The 2024 Annual Drinking Water Quality Report confirms compliance with all EPA and Michigan EGLE standards; lead and copper samples in 2024 were all non-detect, and water undergoes microfiltration, disinfection, and fluoridation with no PFAS or radioactive contaminants exceeding limits.