Lake Zurich Water Hardness & Quality Report (2026)

The Village of Lake Zurich Utilities Department manages the water supply and distribution system for the village in Lake County, Illinois, serving approximately 20,000 residents across 6.5 square miles. Water is sourced exclusively from local groundwater wells, with no surface water intake. The system includes softening treatment facilities that process water prior to distribution through 113 miles of mains and two elevated storage tanks. Annual Consumer Confidence Reports are posted by July 1 on the village website. Utility Superintendent Steve Schmitt may be reached at 847-550-1773.

The supply originates from the Lake Michigan watershed's groundwater sub-basin in northeastern Illinois, underlain by Paleozoic carbonate rock formations including Silurian-age dolomite and limestone of the Racine and Waukegan Formations, overlain by Pleistocene glacial drift aquifers. These geological layers, rich in calcium and magnesium-bearing minerals, impart a hard character to the water through natural dissolution. Inland from Lake Michigan, the absence of the lake's diluting effect allows higher mineral concentrations compared to Chicago-area supplies, with treatment facilities addressing this inherent hardness.

At very hard levels, scale buildup accelerates in water heaters, dishwashers, tea kettles, and washing machines, reducing efficiency by up to 50% and shortening appliance life. Faucets and fixtures develop stubborn deposits, while laundry feels stiff without softeners. Installing a whole-house water softener is recommended; regenerate with salt monthly and clean aerators quarterly. Use vinegar soaks for descaling and low-phosphate detergents to mitigate effects. Village treatment includes lime softening, aeration, filtration, and disinfection, with pH stabilized post-treatment around 7.5–8.5 and recent CCRs noting no lead or copper action exceedances.