Haverhill Water Hardness & Quality Report (2026)

Haverhill, Massachusetts, the Essex County seat on the Merrimack River at the New Hampshire border — a historic shoe-manufacturing city and the birthplace of poet John Greenleaf Whittier — draws its municipal water supply from the Merrimack River and Lake Kenoza (a local impoundment in the Haverhill watershed) via the City of Haverhill Water Department, treating Merrimack River water for the Haverhill area. Water hardness in Haverhill measures 60 mg/L — classified as moderately soft.

Haverhill's soft supply reflects the Merrimack River's origin in the New Hampshire White Mountains and central New Hampshire crystalline highlands. The Merrimack River at Haverhill has drained: the White Mountain batholith (Devonian White Mountain Magma Series — the Concord granodiorite, Conway Granite, and Belknap Mountains Complex — calcium-poor granitic terrain of central New Hampshire); the New Hampshire Merrimack Group (Ordovician–Silurian Littleton Formation, Ammonoosuc Volcanics — metamorphic schist and siliceous volcanic arc sequence — calcium-poor); and the Massachusetts Merrimack Valley lower reach calcareous glacial drift (modest calcium contribution). The New Hampshire granitic and metamorphic headwaters produce naturally soft Merrimack River water, maintained at the 60 mg/L moderate softness by the time the river reaches Haverhill.

With hardness at 60 mg/L, Haverhill residents enjoy moderately soft water with minimal scale challenges. City of Haverhill Water Department consistently delivers water meeting all Massachusetts MassDEP and EPA Safe Drinking Water Act requirements.