Bristol Water Hardness & Quality Report (2026)

Bristol, Connecticut, in Hartford County in the Farmington Valley — historically one of the most important clockmaking and manufacturing cities in the United States, and the headquarters of ESPN — draws its municipal water supply from Bunnell Pond, Lake Compounce Reservoir, and the Bristol Reservoir system via the City of Bristol Utilities Water Division, treating local Farmington Valley watershed reservoirs for Bristol. Water hardness in Bristol measures 70 mg/L — classified as moderately soft.

Bristol's moderate softness reflects the Farmington Valley watershed's mixed geology. The Bristol watershed in central Hartford County drains: the Metacomet Ridge — the iconic basalt trap rock ridge formed from Jurassic Talcott and Hampden Basalt (CAMP — Central Atlantic Magmatic Province flood basalt flows — calcium-poor mafic volcanic rock); the Hartford Basin Triassic New Haven Formation arkosic sandstone (moderately calcareous from feldspar dissolution); and some Proterozoic crystalline gneiss of the Hartford Dome. The dominant Jurassic basalt of the Metacomet Ridge is calcium-poor, contributing to the soft supply. The moderate 70 mg/L reflects some calcareous input from the Triassic sandstone and thin limestone lenses in the Hartford Basin.

With hardness at 70 mg/L, Bristol residents enjoy moderately soft water with minimal scale challenges. City of Bristol Utilities Water Division consistently delivers water meeting all Connecticut DEEP and EPA Safe Drinking Water Act requirements.