New York City drinking water supply and quality report 2024
In 2024, New York City’s water supply system delivered more than one billion gallons of safe, high-quality drinking water each day to over 8.2 million city residents and about one million people in surrounding counties. The water flowed from 19 reservoirs and three controlled lakes spread across a nearly 2,000-square-mile watershed in the Catskill Mountains and Hudson Valley. The Catskill/Delaware system supplied 92.7% of the water, while the Croton system provided 7.3%.
The Catskill/Delaware supply, one of the few large unfiltered surface water systems in the nation, was treated with chlorine and ultraviolet light, along with additional chemicals to control corrosion and protect dental health. The Croton supply was fully filtered at the Croton Water Filtration Plant and treated with similar disinfection processes. Throughout the year, DEP conducted extensive monitoring, performing more than 396,850 analyses on over 33,750 distribution system samples, along with approximately 254,750 analyses and 2.9 million robotic measurements in the watershed, confirming that New York City’s drinking water met all state and federal standards in 2024