Attleboro Water Hardness & Quality Report (2026)

Attleboro, Massachusetts, in Bristol County — a major Bristol County industrial and jewelry manufacturing city (historically the 'Jewelry Capital of the World' — Attleboro produced a significant fraction of all US costume jewelry from the late 19th to mid-20th century), adjacent to Providence, Rhode Island, a diverse city with significant Portuguese-American and Cape Verdean communities, and a growing southeastern Massachusetts suburban–industrial community — draws its municipal water supply from the Ten Mile River watershed reservoirs via the City of Attleboro Water Division. Water hardness in Attleboro measures 86 mg/L — classified as moderately soft.

Attleboro's moderate softness reflects the Bristol County watershed's calcareous-poor Avalonian crystalline geology. The Ten Mile River watershed drains the Attleboro–North Attleboro area — predominantly Proterozoic Avalonian Terrain (the Attleboro Granite and Blackstone Group metasedimentary rocks — calcium-poor Precambrian crystalline terrain of the southeastern Massachusetts–Rhode Island Avalon terrane). The Attleboro Water Division's reservoir supply from this calcareous-poor crystalline catchment, supplemented by effective water treatment, produces the moderate 86 mg/L — typical for southeastern Massachusetts Avalon terrane supplies.

With hardness at 86 mg/L, Attleboro residents enjoy moderately soft water. City of Attleboro Water Division consistently delivers water meeting all Massachusetts MassDEP and EPA Safe Drinking Water Act requirements.