Niles Water Hardness & Quality Report (2026)

The Village of Niles Public Water System serves approximately 30,000 residents in Niles, Illinois, in Cook County within the Chicago metropolitan area. Water is purchased from the Village of Morton Grove, which draws it from Lake Michigan via a separate intake. Treatment — including clarification and chlorination — is conducted at upstream facilities such as Chicago's Jardine Water Purification Plant or similar providers; Niles itself operates no local treatment plant, distributing water through the municipal system at 6849 Touhy Avenue. Fluoridation is also applied as part of the treatment summary.

Lake Michigan lies within the binational Great Lakes system, its basin underlain by Precambrian crystalline bedrock and overlain by Pleistocene glacial deposits of till, outwash sands, and clays. Glacial scouring limits prolonged contact with calcium- and magnesium-rich limestones, yielding a naturally soft source supply. However, blending or distribution through regional infrastructure can introduce minerals from glacial drift aquifers or deeper Silurian dolomite bedrock in northeastern Illinois, potentially elevating hardness through carbonate dissolution and resulting in a harder character at the tap.

At harder levels, water leaves scale deposits on fixtures, heaters, and pipes, reducing efficiency in water heaters (shortening lifespan by 30–50%), dishwashers, and washing machines through calcium buildup; boilers and faucets may show white crusts. Maintenance includes monthly vinegar descaling, installing drain screens, and annual heater flushes; a water softener is recommended to extend appliance life and prevent spotting on dishes and glassware. The 2022 Annual Drinking Water Quality Report for Niles confirms full compliance with no violations; pH is typically 7.5–8.5 from the Lake Michigan source; treatment includes filtration, disinfection, and fluoridation.