Bloomington Water Hardness & Quality Report (2026)

Bloomington, Minnesota, in Hennepin County south of Minneapolis — home of the Mall of America — draws its municipal water supply through the City of Bloomington Public Works Water Division, sourcing from the Mississippi River via treated water contracts with Minneapolis Water Works (Minneapolis's Fridley Water Treatment Plant) and from local Jordan Aquifer groundwater wells (the Cambrian Jordan–Mt. Simon Sandstone aquifer beneath the Twin Cities metro). Bloomington blends surface water and deep groundwater in its distribution system. Water hardness measures 131 mg/L — classified as moderately hard.

Bloomington's moderate hardness reflects the blended supply of Mississippi River surface water and Jordan Aquifer groundwater. The Mississippi River at Minneapolis collects drainage from the Minnesota Superior Upland — Precambrian granite and Cretaceous plains — with accumulated hardness from the diverse upstream watershed. The Jordan Aquifer (Cambrian Jordan Sandstone) in the Twin Cities metro draws from a confined deep aquifer — the Jordan Sandstone is a very permeable quartz sand that produces high-quality water but with moderate mineral content from the calcareous Cambrian sea environment. The 131 mg/L reading reflects the blend of the Mississippi surface supply and Jordan aquifer groundwater in Bloomington's distribution system.

With hardness at 131 mg/L, Bloomington residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. Dishwashers produce cleaner glassware with rinse-aid. City of Bloomington Public Works and Minneapolis Water Works consistently deliver water meeting all Minnesota MDH and EPA Safe Drinking Water Act requirements.