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New Haven Water Quality: Lead Service Lines, PFAS, and Connecticut's Aging Infrastructure

March 20, 2026
New Haven Connecticut skyline with Yale University campus and Long Island Sound

Protected Sources, Old Pipes

South Central Connecticut Regional Water Authority (RWA) supplies drinking water to approximately 430,000 people in the Greater New Haven area, including New Haven, Hamden, East Haven, Branford, and surrounding towns. The system relies primarily on surface water from a network of reservoirs — Lake Whitney, Lake Saltonstall, Lake Gaillard, and others — nestled in the forested hills north and east of the city.

These reservoirs benefit from extensive watershed protection. RWA owns thousands of acres of land surrounding its water sources, limiting development and contamination risk. The source water is consistently high quality, requiring conventional treatment (coagulation, filtration, disinfection) but starting from a clean baseline.

The challenge — as in many Northeast cities built in the 1800s and early 1900s — is what happens after treatment. New Haven’s distribution system includes miles of aging pipes, and the city has a significant number of lead service lines connecting water mains to homes.

Lead: New Haven’s Infrastructure Legacy

New Haven’s housing stock is among the oldest in Connecticut. Many homes in the city — a pattern familiar to residents of Newark and Pittsburgh —'s neighborhoods — Fair Haven, the Hill, Newhallville, Dixwell, Westville — were built in the late 1800s and early 1900s when lead was the standard material for service line connections and interior plumbing solder.

RWA has been conducting a lead service line inventory as required by the EPA’s revised Lead and Copper Rule. The utility uses corrosion control treatment (optimized pH and alkalinity adjustment) to minimize lead leaching from pipes, and system-wide 90th percentile testing has generally remained below the EPA’s action level of 15 ppb.

However, individual homes with lead service lines can experience elevated lead levels, particularly:

New Haven’s lead exposure risk is compounded by the city’s socioeconomic profile — the city has one of the highest child poverty rates in Connecticut, and lead-contaminated drinking water adds to existing lead exposure from paint in older housing.

PFAS: Connecticut’s Growing Concern

Connecticut has been at the forefront of PFAS regulation — see also our coverage of Hartford —, driven by contamination discoveries at multiple sites across the state. The Connecticut Department of Public Health established action levels for PFAS in drinking water — 70 ppt for the sum of five PFAS compounds — before the EPA’s 2024 federal rule set even stricter limits.

For New Haven specifically, PFAS concerns relate to:

RWA has been testing for PFAS across its system under both state requirements and the EPA’s UCMR 5 program. Results have generally shown low levels, but the new federal MCLs (4 ppt for PFOA and PFOS individually) set a high bar that will require ongoing vigilance.

Disinfection and Water Age

RWA uses chloramine for secondary disinfection in its distribution system — maintaining a residual disinfectant throughout the miles of pipes that deliver water to homes and businesses. Chloramine produces fewer taste and odor complaints than free chlorine and generates lower levels of regulated disinfection byproducts (TTHMs and HAAs).

However, water age can be a concern in parts of the distribution system with lower demand. When water sits in pipes longer, disinfectant residual can drop (potentially allowing bacterial regrowth) and disinfection byproducts can increase. RWA manages this through flushing programs and pressure zone management.

Combined Sewer Overflows

Like many older New England cities, New Haven has a combined sewer system that carries both stormwater and sanitary sewage in the same pipes. During heavy rain events, the system can overflow, discharging a mix of untreated sewage and stormwater into New Haven Harbor and Long Island Sound.

While this doesn’t directly contaminate the drinking water supply (RWA’s reservoirs are separate from the harbor), it reflects the broader infrastructure challenge facing the city and can affect recreational water quality in coastal areas.

Climate Change and Water Supply

Connecticut’s changing climate presents both opportunities and challenges for New Haven’s water supply. Increased precipitation in the Northeast has generally kept reservoirs well-supplied, but the pattern of that precipitation is changing — more intense storms separated by longer dry periods.

Warmer water temperatures in reservoirs can promote algal growth (including potential harmful algal blooms), increase organic matter that leads to disinfection byproduct formation, and alter the treatment process requirements. RWA has been monitoring for these trends and adjusting treatment accordingly.

What Residents Can Do

If you’re concerned about your water quality, a certified water treatment professional can test your water and recommend solutions tailored to New Haven’s specific water chemistry.

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