Auburn Gresham Water Hardness & Quality Report (2026)

Auburn Gresham is served by the City of Chicago Department of Water Management, which operates the Jardine Water Purification Plant and the Sawyer Water Purification Plant on the shores of Lake Michigan. These plants treat surface water from Lake Michigan and distribute it throughout Chicago's community areas, including Auburn Gresham. In addition, the city supplements its supply with groundwater from deep wells tapping the Cambrian–Ordovician aquifer system underlying northeastern Illinois. The utility serves Cook County and portions of surrounding counties, providing treated water to homes, businesses, and institutions in the Auburn Gresham service area.

The primary surface-water source is the Lake Michigan watershed, draining a large glacial basin and delivering relatively soft, low-mineral water. The groundwater component comes from the Cambrian–Ordovician sandstone aquifer, overlain by Ordovician dolomites and limestones rich in calcium and magnesium. As groundwater moves through these carbonate-rich formations it dissolves minerals, producing a hard supply. The combination of soft lake water and hard groundwater yields a mixed-source system with a moderately mineralised to hard overall character.

At hard water levels, residents can expect visible scale buildup on faucets, showerheads, and inside water heaters, as well as reduced soap and detergent lathering. Dishwashers, washing machines, and tank-style water heaters are most affected, requiring more frequent descaling and maintenance. A water softener is commonly recommended to reduce scale, extend appliance life, and improve bathing and laundry comfort. Chicago's water is treated via coagulation, sedimentation, filtration, and chloramination; older homes with lead service lines may still experience elevated lead at the tap, and PFAS monitoring results are reported in the city's annual Consumer Confidence Report.