New York City – New York
New York City manages one of the most extensive municipal water systems in the world, providing approximately 1.1 billion gallons of high-quality drinking water daily to over 9 million people. The system draws water from a network of 19 reservoirs and three controlled lakes spanning nearly 2,000 square miles in the Hudson Valley and Catskill Mountains.
NYC’s water supply is remarkable for operating largely unfiltered, with 90% of the city’s water coming from the Catskill/Delaware watershed that operates under a Filtration Avoidance Determination (FAD). This designation from the EPA acknowledges the exceptional quality of the source water and the city’s comprehensive watershed protection program. The remaining 10% comes from the Croton watershed, which undergoes filtration at a state-of-the-art plant completed in 2015.
New York City Water Quality: Current Status (2024-2025)
Latest Testing Results
- Compliance Status: NYC’s water system meets or exceeds all federal and state water quality standards. For the latest quarter assessed by the EPA (April-June 2024), NYC’s tap water was in full compliance with health-based drinking water standards.
- PFAS Levels: Unlike many water systems across the country, New York City’s drinking water shows no detectable levels of the 29 PFAS compounds that were recently regulated by the EPA. The city’s watershed protection program has successfully kept these “forever chemicals” out of the water supply.
- Lead Testing: The NYC water supply system does not contain lead service lines or lead mains. However, lead can leach from household plumbing in older buildings. The city treats water with orthophosphate to create a protective coating inside pipes that prevents lead from leaching into water.
Water Sources and Treatment
- The Catskill/Delaware System: Provides approximately 90% of the city’s drinking water and consists of six reservoirs in the Catskill Mountains, located up to 125 miles north of NYC. This water undergoes disinfection with chlorine and ultraviolet light but is not filtered.
- The Croton System: Supplies the remaining 10% of NYC’s water and consists of 12 reservoirs and three controlled lakes in Westchester, Putnam, and Dutchess counties. This water passes through the Croton Water Filtration Plant, which uses advanced treatment technologies to remove impurities.
- Treatment Process: All NYC water is treated with chlorine to kill harmful bacteria, fluoride to help prevent tooth decay, orthophosphate for corrosion control, and sodium hydroxide to adjust pH. Water from the Catskill/Delaware system also receives UV disinfection.
Watershed Protection
- Land Acquisition Program: The city has purchased or protected through conservation easement over 130,000 acres of watershed land since 1997 to maintain water quality and prevent contamination.
- Regulatory Oversight: NYC’s Filtration Avoidance Determination (FAD) requires strict monitoring and protection of the Catskill/Delaware watershed. The current FAD issued in 2017 extends through 2027.
- Source Investigations: The Department of Environmental Protection (DEP) is proactively investigating potential sources of PFAS in the watershed, despite current testing showing no detectable levels, to safeguard future water quality.
Infrastructure Projects
NYC is currently undertaking one of its largest infrastructure projects – connecting a bypass tunnel around leaks in the Delaware Aqueduct. This 85-mile-long aqueduct delivers about half of the city’s water supply from four western Catskill Mountain region reservoirs. The project, estimated at $1 billion, includes a 2.5-mile bypass tunnel being built 600 feet beneath the Hudson River. During the connection process, NYC will rely more heavily on the Croton system and water conservation measures.
Recommendations for NYC Residents
Check Your Building’s Plumbing
If you live in a building constructed before 1986, your internal plumbing may contain lead solder or fixtures. Consider having your water tested for lead, especially if you have young children or are pregnant.
Flush Your Pipes
If water has been sitting in pipes for more than six hours, run your tap until the water is noticeably colder before using it for drinking or cooking. This helps clear water that may have absorbed lead or other contaminants from plumbing.
Stay Informed
Read NYC’s annual Drinking Water Supply and Quality Report, available on the DEP website. The report provides detailed information about water quality testing results and ongoing watershed protection efforts.
Use Cold Water for Consumption
Always use cold water for drinking, cooking, and preparing baby formula. Hot water is more likely to contain higher levels of lead and other metals from your plumbing system.
Conserve Water
Help protect NYC’s water system by conserving water, especially during the Delaware Aqueduct repair work. Fix leaks promptly, use water-efficient appliances, and follow the city’s guidance during drought conditions.
Frequently Asked Questions
Why doesn’t NYC filter most of its water?
New York City is one of only five large cities in the United States with a surface water supply that does not require filtration. This is possible because of the exceptional quality of the source water from the Catskill and Delaware watersheds and the city’s comprehensive watershed protection program. The EPA has granted NYC a Filtration Avoidance Determination, which saves the city billions in infrastructure costs while still ensuring safe drinking water. The water does receive disinfection through chlorination and UV treatment.
Does NYC water contain PFAS or “forever chemicals”?
Unlike many water systems across the United States, New York City’s drinking water currently shows no detectable levels of the 29 PFAS compounds that the EPA tests for. This is remarkable considering that nearly half of tap water nationwide contains at least one type of these chemicals. NYC’s Department of Environmental Protection is proactively investigating potential sources of PFAS in the watershed to maintain this high level of water quality, even though the city already meets the new stringent federal standards.
Should NYC residents worry about lead in their water?
NYC’s water distribution system does not have lead service lines or lead mains. However, buildings constructed before 1986 may have lead in their internal plumbing, such as lead solder connecting copper pipes or fixtures containing lead. The city treats water with orthophosphate, which creates a protective coating inside pipes to prevent lead from leaching into the water. If you live in an older building and are concerned about lead, consider having your water tested, especially if you have young children or are pregnant. Always run your tap until the water is cold before using it for drinking or cooking after long periods of non-use.
Why does NYC water taste different sometimes?
The taste of NYC tap water can vary depending on which reservoir system is supplying your neighborhood. Water from the Catskill/Delaware system (west of the Hudson River) and the Croton system (east of the Hudson) can taste different due to variations in geology, soil conditions, and naturally occurring minerals in their respective watersheds. Additionally, during maintenance or drought conditions, the city may change the proportion of water coming from each system, which can affect taste. These variations are normal and do not indicate any safety concerns. The city also maintains a current water distribution map on the DEP website showing which system is supplying different parts of the city.
Please read – our information
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