Merrimack Water Hardness & Quality Report (2026)

Merrimack, New Hampshire, in Hillsborough County — a major south New Hampshire suburban and corporate community (Merrimack is a significant Hillsborough County town — a south New Hampshire suburb adjacent to Nashua and Bedford; Merrimack is one of the most important corporate communities in New Hampshire — the home of Anheuser-Busch's (now AB InBev's) Merrimack Brewery (one of the largest breweries in New England — the Merrimack brewery produces Budweiser and other AB InBev brands for the northeastern market; the brewery opened in 1970 and has been a major employer and community institution in Merrimack); Merrimack is also the home of BAE Systems' major New Hampshire operations (a significant defense electronics employer in the south New Hampshire corridor); Merrimack has been one of the most economically dynamic communities in south New Hampshire, benefiting from the Massachusetts border proximity and New Hampshire's tax advantage (no sales tax or income tax), a diverse Hillsborough County community with a primarily professional, technology, and suburban family population — draws its municipal water supply via the Pennichuck Water Works. Water hardness in Merrimack measures 61.5 mg/L — classified as moderately soft.

Merrimack's moderate softness reflects the south New Hampshire Hillsborough County Merrimack River granite watershed's calcareous-poor character. The Merrimack River watershed drains the Precambrian New Hampshire Highlands granite with effective treatment, producing the moderately soft 61.5 mg/L.

With hardness at 61.5 mg/L, Merrimack residents enjoy moderately soft water. Pennichuck Water Works consistently delivers water meeting all New Hampshire DES and EPA Safe Drinking Water Act requirements.