Upper Alton Water Hardness & Quality Report (2026)

Upper Alton, Illinois is served by the Alton Public Water Supply, part of the broader Alton area utilities potentially linked to Illinois American Water operations. The primary source is the Mississippi River, with intake and treatment at the Alton Water Treatment Plant. Service covers Madison County, including the Upper Alton neighborhood and surrounding communities. Treatment includes sodium hydroxide for corrosion control, coagulation, filtration, chlorination, and fluoridation to meet state and federal standards.

The Mississippi River watershed spans the Upper Mississippi River Basin, with local geology dominated by Paleozoic limestone and dolomite formations — including the Ordovician Galena Group and Silurian dolomites exposed along the river bluffs. These carbonate rocks contribute to a hard supply through natural dissolution, elevating mineral content. The river integrates drainage from limestone-rich tributaries and flows through glacial drift and loess-covered regions, producing a mineralised character typical of Midwestern floodplain aquifers.

At 293 mg/L (very hard), scale buildup is significant in pipes, heaters, and fixtures, most affecting water heaters, dishwashers, and laundry machines — reducing efficiency and lifespan. White deposits on faucets and glassware are common; maintenance includes periodic vinegar descaling and sediment filters. A water softener is strongly recommended to mitigate these effects and protect appliances. Recent 2025 reports show compliance with lead and copper rules via optimised corrosion control; no specific PFAS detections were noted, though routine monitoring occurs.