Orland Park Water Hardness & Quality Report (2026)

Orland Park, Illinois, in southwest Cook County — one of the most prosperous southwest Chicago suburbs, a major retail hub (Orland Square Mall), and a key Southwest suburban commuter community — draws its municipal water supply from Lake Michigan via the City of Chicago Department of Water Management (DWM) through the South Suburban Water Commission, distributed to Orland Park by the Village of Orland Park Public Works Department. Water hardness in Orland Park measures 129 mg/L — classified as moderately hard.

Orland Park's moderate hardness reflects the southwest Cook County Lake Michigan metropolitan distribution zone. Lake Michigan water at the Chicago DWM intake has moderate calcareous content from the Great Lakes Basin carbonate geology. The South Suburban Water Commission distribution to the southwest Cook County communities (Orland Park, Tinley Park, Palos areas) uses a relatively modern transmission infrastructure associated with the 1960s–1980s southwest suburban expansion — newer than the inner Chicago northwest corridor infrastructure, contributing to the somewhat lower hardness (129 mg/L) compared to older Chicago northwest suburban zones (Des Plaines: 151.5 mg/L). The southwest suburban distribution benefits from more recent pipe replacement programs.

At 129 mg/L, Orland Park residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. Village of Orland Park Public Works Department consistently delivers water meeting all Illinois EPA and federal EPA Safe Drinking Water Act requirements.