Westmont Water Hardness & Quality Report (2026)

The Westmont Public Works Department manages the water utility, serving approximately 25,334 residents in Westmont, Illinois, within DuPage County. Water is purchased as treated surface water from the City of Chicago via the DuPage Water Commission. The source is Lake Michigan, with treatment occurring at Chicago's facilities including clarification and chlorination using hypochlorite. No local treatment is applied by Westmont. The utility can be reached at 630-981-6270 or pw@westmont.il.gov at 31 W. Quincy St, Westmont, IL 60559.

Lake Michigan forms the primary watershed, a massive freshwater body spanning four states with inflows from rivers draining diverse geologies including Paleozoic limestone and shale. The basin's glacial history has deposited Pleistocene drift layers that interact with surface waters, imparting dissolved minerals characteristic of a hard supply. Carbonate bedrock in tributary areas contributes calcium and magnesium to the water's mineral profile, while the lake's vast volume moderates extremes yet retains a consistently mineralised character from ongoing geological interactions.

Hard water in Westmont leads to scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency most severely in heated appliances. Soap lathering is inefficient, leaving residue on dishes and skin. Maintenance includes regular descaling of fixtures, cleaning aerators, and flushing hot water systems. A water softener is recommended to mitigate scaling and extend appliance life. The 2022 Annual Water Quality Report confirms compliance with Safe Drinking Water Act standards; two contaminants exceeded health guidelines in past tests but no EPA violations were noted.