New York City Water Quality Guide

New York City's water supply is one of the largest unfiltered surface water systems in the United States, serving approximately 9 million people daily. The water comes from a network of 19 reservoirs and three controlled lakes located in the Catskill Mountains and the Hudson Valley, spanning a watershed of nearly 2,000 square miles.

The Three Watershed Systems

Why NYC Water Is Unfiltered

NYC is one of only five major U.S. cities with a surface water supply pure enough to avoid filtration requirements. The EPA granted this Filtration Avoidance Determination (FAD) because the protected watershed produces exceptionally clean source water. The city invests heavily in watershed protection, including land acquisition, septic system upgrades, and agricultural best practices programs, to maintain this status.

While the water isn't filtered, it does receive treatment: chlorine for disinfection, ultraviolet light to inactivate microorganisms, fluoride for dental health, and orthophosphate to reduce lead leaching from pipes.

New York City water consistently rates among the best municipal water supplies in the country. The Department of Environmental Protection (DEP) tests the water more than 500,000 times per year at over 1,000 sampling stations throughout the system.

Water Quality Report Highlights

According to NYC's annual water quality report, the system consistently meets or exceeds all EPA and New York State drinking water standards. The water is naturally low in minerals, giving it a clean taste that many residents and visitors appreciate. NYC water is famously credited for the quality of the city's bagels and pizza.

Taste and Aesthetics

NYC water is often praised for its taste. The low mineral content and soft water characteristics contribute to a clean, crisp flavor. However, some residents may notice a slight chlorine taste, which varies seasonally. Running cold water for a minute or using a pitcher with a basic carbon filter can reduce this taste if desired.

Despite NYC's high-quality source water, lead contamination remains a concern due to the city's aging building infrastructure. Lead doesn't come from the reservoir system or city water mains; it leaches from pipes, solder, and fixtures inside buildings.

NYC's Lead Mitigation Efforts

The city adds orthophosphate to the water supply, which creates a protective coating inside pipes that reduces lead leaching. This corrosion control treatment has significantly lowered lead levels across the system. NYC's water system meets EPA lead action levels, with 90th percentile testing showing lead below 15 parts per billion (ppb).

Who Is Most at Risk?

• Pre-war buildings: Apartments in buildings built before 1961 are more likely to have lead pipes
• NYCHA housing: Some public housing complexes have documented lead concerns
• Schools and daycares: Older facilities have been tested and remediated under city programs
• Single-family homes: Houses built before 1987 may have lead solder

The building owner, not the city, is responsible for internal plumbing. Renters should request information about their building's plumbing from landlords or management companies.

While NYC water meets all federal standards, testing your own tap water provides certainty about what you're actually drinking. Lead levels can vary significantly between buildings and even between apartments in the same building.

Who Should Test

• Residents of buildings constructed before 1961
• Families with children under 6 years old
• Pregnant women or those planning pregnancy
• Anyone who has never tested their tap water
• After any plumbing work or extended vacancy

Free Testing in NYC

What Your Results Mean

• Under 1 ppb: Excellent; minimal lead present
• 1-5 ppb: Low level; safe for most but consider filtration for young children
• 5-15 ppb: Moderate; use NSF 53 certified filter, especially for children
• Over 15 ppb: Exceeds EPA action level; use filtered/bottled water, notify DEP

Daily Water Use Tips

• Flush before drinking: Run cold water for 30 seconds to 2 minutes before drinking, especially in the morning or after being away
• Use cold water: Never use hot tap water for drinking, cooking, or baby formula (hot water leaches more lead)
• Clean aerators: Debris can accumulate in faucet screens; clean them periodically

Filtration Options

Most NYC residents don't need filtration for general water quality, but filters can address specific concerns:

• For lead: NSF 53 certified filters (pitcher, faucet-mount, or under-sink)
• For chlorine taste: Basic carbon filters (NSF 42) like standard Brita pitchers
• For comprehensive protection: Reverse osmosis systems

Seasonal Considerations

NYC water quality can vary slightly by season. Spring runoff may increase turbidity temporarily, and chlorine levels may be adjusted seasonally. These variations are within safe limits but may affect taste. The DEP publishes monthly water quality reports for transparency.

All five boroughs receive the same high-quality water from the Catskill/Delaware and Croton systems. However, building age and infrastructure vary:

• Manhattan: Many pre-war buildings; higher likelihood of lead plumbing in older structures. High-rise buildings may have rooftop water tanks that require maintenance.
• Brooklyn: Mix of old and new construction; brownstones may have original plumbing. Rapid development means new buildings with modern plumbing.
• Queens: Suburban-style housing stock varies widely in age. Many post-war homes have copper pipes but possibly lead solder.
• The Bronx: NYCHA housing has received attention for lead testing. Many apartment buildings are older and should be tested.
• Staten Island: More single-family homes; owners have direct control over testing and remediation.

Regardless of borough, building age is the primary factor for lead risk. Request information from your building management or test independently.