Logan Square Water Hardness & Quality Report (2026)

Logan Square, Illinois — a vibrant Chicago neighborhood on the northwest side in Cook County, bounded by the Kennedy Expressway (I-90) and known for its historic boulevards and diverse population — receives its municipal water supply from the City of Chicago Department of Water Management (DWM), drawing Lake Michigan water treated at the Jardine Water Purification Plant and distributed through the northwest Chicago neighborhood infrastructure. Logan Square sits in the northwest side distribution zone north of the Eisenhower Expressway corridor. Water hardness in Logan Square measures 170.5 mg/L — classified as hard.

Logan Square's moderately high hardness reflects the northwest Chicago DWM distribution zone. The Logan Square area is served through the northwest side distribution network — cast-iron and ductile iron mains of varying vintages from the 1900s–1960s construction eras in the densely built northwest residential corridor. The 170.5 mg/L reading in Logan Square is somewhat higher than Chicago's central zones and lower than neighboring Belmont Cragin (139.5 mg/L — west of Logan Square, served by the same northwest corridor but with different pressure and pipe vintage characteristics). Logan Square's historic 1920s–1930s grey-stone neighborhood density and cast-iron service line network contribute to the moderately elevated hardness above the Lake Michigan source baseline.

At 170.5 mg/L, Logan Square residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and appliances within weeks — monthly descaling with citric acid solution is standard maintenance. Chicago DWM consistently delivers water meeting all Illinois EPA and federal EPA Safe Drinking Water Act requirements.