Buffalo Grove Water Hardness & Quality Report (2026)

The Village of Buffalo Grove Public Works Department supplies treated drinking water to Buffalo Grove in Lake and Cook Counties, Illinois, serving approximately 43,000 residents across 10.6 square miles. All water is sourced from Lake Michigan via the City of Evanston, which treats and delivers finished surface water through the Northwest Water Commission. There are no local treatment plants; the village manages distribution and monitoring only. Treatment by Evanston includes coagulation, sedimentation, filtration, and disinfection with chlorine before delivery to the distribution network.

The water originates from the Lake Michigan watershed within the Great Lakes-St. Lawrence River basin, shaped by glacial deposits and Paleozoic carbonate rock formations including Silurian dolomite and Devonian limestone exposed around the lake basin. These geological features contribute dissolved calcium and magnesium, producing a characteristically hard supply. Surface water passes through limestone-rich tributaries and shoreline zones, acquiring minerals without the deep aquifer filtration that might otherwise moderate hardness, while karst-influenced limestones in northeastern Illinois further promote mineral leaching.

Hard water promotes scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. White mineral deposits on fixtures and reduced water pressure from pipe narrowing are common effects. Regular maintenance such as vinegar descaling, installing scale-inhibiting filters, or whole-house softening is recommended to protect appliances. A water softener is highly advised for households experiencing dry hair, skin irritation, or appliance problems. The 2023 average pH was 7.48, and the system complies with EPA Safe Drinking Water Act standards for lead and copper via corrosion control.