Bloomington Water Hardness & Quality Report (2026)

The City of Bloomington Utilities Department serves approximately 90,000 residents across 19 square miles in Hennepin County, Minnesota, within the southern Twin Cities metropolitan area. Water is sourced exclusively from the Bloomington Aquifer wells drawing from the Jordan Aquifer. The primary treatment facility is the city's Water Treatment Plant, which employs lime softening, filtration, and disinfection with chloramination before distribution through an extensive pipeline network. No surface water sources are utilized; the supply originates within the Upper Mississippi River watershed, overlying the Twin Cities Basal Aquifer.

Geologically, the supply draws from the Cambrian Jordan Sandstone aquifer, confined by overlying Ordovician Prairie du Chien Group dolomites and limestones, with deeper Mount Simon Sandstone influence beneath glacial drift. These ancient carbonate and sandstone formations dissolve calcium and magnesium as groundwater flows through the Twin Cities Basal Aquifer system, yielding a naturally hard supply prior to treatment. The city's lime-softening process at the Water Treatment Plant modifies this character, producing soft water at 89 mg/L for distribution.

As a soft water supply post-treatment, Bloomington's water minimizes scale buildup in pipes, water heaters, and dishwashers, reducing energy costs and extending appliance life without frequent deliming. Laundry detergents and soaps lather efficiently, and skin feels less dry after bathing. No home softener is needed or recommended — the utility's lime-softening process already achieves softening, and additional home units could over-soften and cause corrosion risks. The 2025 Consumer Confidence Report confirms EPA compliance for pH stable at 7.5–8.5, lead at 90th percentile 3 ppb below action level, no PFAS exceedances via granular activated carbon polishing, and fluoride adjusted to 0.7 mg/L.