New London Water Hardness & Quality Report (2026)

New London, Connecticut, in New London County — a major southeast Connecticut maritime and submarine base city (New London is a significant New London County city — one of the most historically important maritime cities in New England; New London was a major whaling port in the 19th century (New London was the second most important whaling port in the United States in the mid-19th century, after New Bedford, MA; the New London whaling industry at its peak had dozens of whaling ships and produced some of the most significant maritime fortunes in Connecticut history)); New London is home of the United States Coast Guard Academy (one of the five federal service academies — the USCG Academy is the smallest of the federal academies and is consistently one of the most competitive to enter; New London's identity as a Coast Guard city is central to its character) and is adjacent to Naval Submarine Base New London (the primary submarine base on the East Coast — 'The Home of the Submarine Corps'); New London is also home of Connecticut College (a selective liberal arts college), a diverse New London County community — draws its municipal water supply via the City of New London Water Division. Water hardness in New London measures 83.5 mg/L — classified as moderately soft.

New London's moderate softness reflects the southeast Connecticut Thames River watershed's calcareous-poor crystalline geology. The Thames River watershed at New London drains the Precambrian Connecticut gneiss (calcareous-poor). City of New London treatment produces the moderately soft 83.5 mg/L.

With hardness at 83.5 mg/L, New London residents enjoy moderately soft water. City of New London Water Division consistently delivers water meeting all Connecticut DEEP and EPA Safe Drinking Water Act requirements.