Alton Water Hardness & Quality Report (2026)

Alton, Illinois, in Madison County — a major southwest Illinois Mississippi River blufftop city (Alton is a significant Madison County city — a southwest Illinois city perched on dramatic limestone bluffs above the Mississippi River; Alton is known for its extraordinary antebellum history (Alton was the site of the Lovejoy Abolitionist Press (the 1837 murder of abolitionist newspaper editor Elijah Lovejoy by a pro-slavery mob — one of the most significant events in the history of American abolitionism; Lovejoy became a martyr for freedom of the press and the abolitionist cause; his monument stands in Alton to this day); Alton was the site of the last Lincoln–Douglas Debate (the seventh and final debate between Abraham Lincoln and Stephen Douglas in 1858 — held in Alton; the Lincoln–Douglas debates are one of the most important series of public debates in American political history); Alton is said to be the birthplace of Robert Wadlow (the tallest person in recorded history — Robert Wadlow of Alton stood 8 ft 11.1 in; his life-size bronze statue is one of the most visited landmarks in Alton)), a diverse Madison County community with a significant African-American, working-class, and Mississippi River heritage population — draws its municipal water supply from the Mississippi River via the City of Alton Water Division. Water hardness in Alton measures 215 mg/L — classified as hard.

Alton's hard supply reflects the southwest Illinois Madison County Mississippi River corridor's calcareous character. The Mississippi River at Alton carries dissolved minerals from the upper Midwest, and limited softening produces the hard 215 mg/L.

At 215 mg/L, Alton residents face regular hard water challenges. Monthly descaling and water softeners are recommended. City of Alton Water Division consistently delivers water meeting all Illinois EPA and federal EPA Safe Drinking Water Act requirements.