New Haven County, Connecticut: drinking water report. New Haven County in southern Connecticut has about 864,000 residents, including New Haven (home to
New Haven County in southern Connecticut has about 864,000 residents, including New Haven (home to Yale University), Waterbury, and Meriden. The South Central Connecticut Regional Water Authority draws from a network of 24 reservoirs across 27,000 acres of watershed land. The system's extensive watershed protection is a genuine asset, but aging infrastructure in the cities and industrial legacy contamination in Waterbury and Naugatuck pose challenges.
Waterbury's brass manufacturing industry operated for over 150 years, earning the city the nickname "Brass City." According to Connecticut DEEP's 2024 environmental site assessment, heavy metal contamination from brass mills – copper, lead, and zinc – persists in soil and groundwater along the Naugatuck River corridor. While the drinking water supply comes from protected reservoirs rather than contaminated groundwater, lead in older building plumbing remains a concern.
The EPA's UCMR5 data detected PFAS at low levels across New Haven County water systems. Tweed-New Haven Airport has documented AFFF use, and industrial sources in the Naugatuck Valley may contribute additional PFAS. A 2024 CT DPH study found one county water system above the state's proposed PFAS action level of 12 ppt.
New Haven County benefits from well-protected reservoir water, but the last mile – pipes within buildings – matters. If you live in a pre-1986 building in New Haven, Waterbury, or other older cities, lead solder in internal plumbing may contribute lead to your tap water.
Check your water for current data. For lead from older plumbing, a certified pitcher or faucet filter is the simplest daily protection. For PFAS, reverse osmosis at the drinking tap adds another layer. Our water filter guide covers both needs. Get your detailed report for historical data, and visit our Connecticut page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover New Haven County, CT.
The EPA places New Haven County, CT in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
Modelled annual fine-particle pollution (PM2.5) in New Haven County, CT averages 7 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide