Hagerstown Water Hardness & Quality Report (2026)

Hagerstown, Maryland, the Washington County seat — a major western Maryland Great Valley city (the 'Hub City' of the Great Valley between the Blue Ridge and South Mountain), a historic Antietam Campaign community (the Battle of Antietam–Sharpsburg took place nearby in September 1862 — the bloodiest single day in American military history with approximately 23,000 casualties), home of the Maryland Theatre, Hagerstown Regional Airport, and a revitalizing western Maryland city and transportation hub at the intersection of I-70, I-81, and US-11 — draws its municipal water supply from the Conococheague Creek and Potomac River via the City of Hagerstown Water Division. Water hardness in Hagerstown measures 182.5 mg/L — classified as hard.

Hagerstown's hard supply reflects the Washington County Maryland Great Valley's highly calcareous carbonate geology. The Conococheague Creek and Potomac River tributaries at Hagerstown drain through: the Cambrian–Ordovician Conococheague Limestone (one of the most calcareous Cambrian limestone formations in the Appalachians — the Cambrian Conococheague Limestone named for the Hagerstown Valley creek, highly calcareous marine carbonate); the Ordovician St. Paul Formation and Chambersburg Limestone (calcareous limestone and dolomite of the Cumberland Valley–Great Valley); and the Hagerstown Valley dolomite (Valley and Ridge Province calcareous dolomite). The Great Valley calcareous carbonate karst produces the hard 182.5 mg/L.

At 182.5 mg/L, Hagerstown residents face regular hard water challenges. Monthly descaling with citric acid solution is standard maintenance. City of Hagerstown Water Division consistently delivers water meeting all Maryland MDE and EPA Safe Drinking Water Act requirements.