Bethlehem Water Hardness & Quality Report (2026)

Bethlehem, Pennsylvania, the Northampton County seat in the Lehigh Valley — famous for Bethlehem Steel, the second-largest US steel company — draws its municipal water supply from the Lehigh River via the City of Bethlehem Water Division, treating Lehigh River water at the Monocacy Creek and Saucon Creek filtration plants serving the Bethlehem metropolitan area. The Lehigh River at Bethlehem has drained the central Pennsylvania Ridge and Valley to the northwest. Water hardness in Bethlehem measures 200.5 mg/L — classified as hard.

Bethlehem's hard supply reflects the Lehigh River watershed's Valley and Ridge carbonate geology upstream of Bethlehem. The Lehigh River above Bethlehem drains: the Ordovician Martinsburg Shale (a calcareous, fine-grained shale of the Great Valley — significant calcium and bicarbonate contribution); the Cambrian Allentown Dolomite (one of Pennsylvania's most reactive carbonate formations — massive calcareous dolomite of the Great Valley sequence); the Cambrian Beekmantown Group dolomite; and the Blue Mountain Precambrian quartzite (soft water contribution). The calcareous Cambrian dolomite formations of the Lehigh Valley's Great Valley Section contribute substantial dissolved calcium to the Lehigh River, producing the hard supply at Bethlehem. The Lehigh Valley's heavy carbonate terrain is reflected consistently in its municipal water hardness.

At 200.5 mg/L, Bethlehem residents face significant hard water challenges. Scale deposits form rapidly on faucet aerators, showerheads, and appliances — monthly descaling with citric acid solution is essential maintenance. City of Bethlehem Water Division consistently delivers water meeting all Pennsylvania DEP and EPA Safe Drinking Water Act requirements.