Chaska Water Hardness & Quality Report (2026)

The Chaska Public Utilities Department serves the city of Chaska in Carver County, Minnesota, providing drinking water to approximately 27,000 residents across a 17-square-mile service area. Water is sourced exclusively from five groundwater wells ranging from 333 to 817 feet deep, all located within the city. The Chaska Water Treatment Plant processes up to 12.6 million gallons per day, applying gravity filtration to remove iron and manganese, disinfection with sodium hypochlorite, and fluoridation as required by federal law. Chaska Utilities can be reached at 952-448-3100.

Chaska's supply originates from the Mt. Simon, Tunnel City-Mt. Simon, Wonewoc-Mt. Simon, Tunnel City-Wonewoc, and Jordan aquifers within the broader Upper Mississippi River Basin watershed. These ancient Cambrian-period sandstone and limestone formations, overlain by glacial deposits, dissolve calcium and magnesium minerals over time, imparting a very hard character to the groundwater. The karst-influenced geology and long residence time in these aquifers shape the water's highly mineralized profile, distinguishing it from surface sources in the region.

At very hard levels, scale buildup accelerates in water heaters, dishwashers, washing machines, and plumbing fixtures, reducing efficiency by up to 50% and shortening appliance lifespan. Boilers and coffee makers are particularly impacted, requiring frequent deliming. A whole-house water softener is strongly recommended for Chaska households to exchange calcium and magnesium for sodium, protecting infrastructure and improving soap efficiency. Regular vinegar flushes for fixtures and low-flow aerators help minimize deposits. The 2025 Drinking Water Report confirms compliance with federal standards; treatment reduces iron and manganese to trace amounts, with no notable contaminants exceeding MCLs per Minnesota Department of Health monitoring.