Lockport Water Hardness & Quality Report (2026)

Lockport, Illinois, in Will County at the historic headwaters of the Illinois and Michigan Canal, receives its municipal water through Illinois American Water, which draws from the Des Plaines River and regional supply networks in the Will County corridor. Lockport sits at the junction of the Chicago Sanitary and Ship Canal and the Cal-Sag Channel — a critical water infrastructure hub for the Chicago metropolitan area. Water supply in this area reflects a blend of Canal-corridor river water and regional groundwater from the Silurian Dolomite Aquifer underlying northeastern Illinois.

The hard 166 mg/L hardness in Lockport reflects the regional dolomite aquifer influence. While Chicago-area Lake Michigan supply typically registers lower hardness (~150 mg/L), Will County's position at the boundary between the Lake Michigan service area and the dolomite plains means local supply incorporates measurable groundwater contributions from the Silurian Niagara Dolomite — the same ancient reef formation producing very hard water in nearby New Lenox (213.5 mg/L) and other Will County communities. This groundwater blending elevates hardness above what the pure canal/river supply would produce.

At 166 mg/L, Lockport's water is solidly hard, and mineral scaling is a routine household reality. Kettles and coffee makers accumulate white deposits within weeks, dishwashers leave mineral film on glassware, and showerheads benefit from regular vinegar soaking. Water heater elements should be inspected annually for scale accumulation. Descaling appliances every two months keeps heating equipment performing efficiently. The moderate PFAS level of 5.9 ppt in this area warrants consideration of a certified drinking water filter for those who prefer an additional layer of protection for daily water consumption.