Sycamore Water Hardness & Quality Report (2026)

The City of Sycamore Water Division serves approximately 17,600 residents in DeKalb County, Illinois. The utility operates five deep wells that access sandstone aquifers, with no surface water component. The Water Division office is located at 202 E. Page Street, Sycamore, IL 60178 (815-895-3545). According to the city's official FAQ, the water supply is classified as very hard, exceeding 180 mg/L of mineral hardness. The utility reports full compliance with all EPA drinking water requirements and sampling and testing standards.

Sycamore's groundwater originates from Paleozoic-age sandstone formations typical of northern Illinois, characteristic of the Illinois Basin. These deep aquifers have undergone extensive contact with mineral-rich sedimentary rock over geological timescales, resulting in elevated dissolved calcium and magnesium—the primary drivers of hardness. Thick sequences of sandstone and limestone create naturally mineralized groundwater, explaining the very hard supply and the region's widespread need for water treatment.

At the very hard classification, residents experience significant scale buildup on fixtures, reduced soap effectiveness, and accelerated wear on water heaters and appliances. The city recommends water softening systems to extend appliance lifespan. The utility applies a phosphate blend corrosion control treatment at individual well sites to manage lead and copper leaching in the distribution system, though source groundwater is lead-free. Third-party analyses have flagged contaminants including Di(2-ethylhexyl) adipate, m-Xylene, 1,1,2-Trichloroethane, and Monochloroacetic acid above EPA health-based guidelines; the city maintains regular testing and publishes results.