Round Lake Water Hardness & Quality Report (2026)

Round Lake Municipal Water Company serves approximately 16,947 residents in Round Lake, Lake County, Illinois, with offices at 442 N. Cedar Lake Road. The utility purchases surface water entirely from Lake Michigan, which is treated and delivered through the Central Lake County Joint Action Water Agency (CLCJAWA). The 2024 Annual Water Quality Report, covering January 1 to December 31, 2024, confirms full compliance with all applicable standards as verified by the Illinois EPA and in-house laboratory testing.

Lake Michigan sits within a vast Great Lakes basin underlain by Paleozoic carbonate bedrock from the Silurian and Devonian periods, including limestone and shale formations. Glacial scouring during the last Ice Age exposed these mineral-rich formations, leaching calcium and magnesium into the lake and producing a hard supply. The watershed also incorporates glacial till and sedimentary deposits that further enhance mineral content. Round Lake's allocation reflects this mineralised character, shaped by carbonate geology and limited dilution from tributaries.

Very hard water promotes heavy limescale buildup in pipes, heaters, and fixtures; hot water heaters may fail 2–3 times faster, while dishwashers and washing machines suffer reduced efficiency. Kettles and faucets show white deposits quickly. Regular vinegar descaling helps, but a whole-house water softener is strongly recommended to protect plumbing, improve soap performance, and extend equipment longevity. The utility monitors pH, lead, and copper per EPA rules, maintaining full compliance. Potential unregulated contaminants including 1,2-Dichloropropane, Nitrite, Alachlor, and Styrene have been flagged in notices; treatment involves screening, coagulation, sedimentation, filtration, and disinfection at CLCJAWA facilities, with ongoing PFAS testing.