New York City Tap Water: What's in It and How to Filter It

Source: NYC DEP 2025 Drinking Water Supply and Quality Report (published 2026) and New York State Department of Health compliance records. Data checked October 2026.

Where NYC Tap Water Comes From

NYC gets its water from 19 reservoirs and 3 controlled lakes. They sit in a watershed of nearly 2,000 square miles, as far as 125 miles north of the city. The system delivers about 1 billion gallons a day. It serves more than 8.8 million city residents, plus over 1 million people in Westchester, Putnam, Orange and Ulster counties.

In 2025, the Catskill and Delaware systems supplied 91.3 percent of the water and the Croton system supplied 8.7 percent. The city also holds a permit for a groundwater supply in southeast Queens. That water has not been delivered to customers in many years.

How the water is treated

• Catskill/Delaware water is not filtered. NYC is one of only five large US cities that does not filter its surface water supply. It runs under a state waiver called the Filtration Avoidance Determination, which lasts through at least 2027. To keep it, DEP spends over $100 million a year protecting the watershed.
• Croton water is filtered at the Croton Water Filtration Plant, an underground plant in the Bronx that uses granular activated carbon and sand filters.
• All water gets chlorine and UV light treatment, plus food grade phosphoric acid and sodium hydroxide to protect pipes from corrosion, and fluoride.

Is the water the same in every borough?

Mostly, yes. All five boroughs are on one public water system (ID NY7003493). They get the same treatment and the same yearly test report. The source is not the Hudson River. It is a network of upstate reservoirs: the Catskill and Delaware systems west of the Hudson, and the Croton system east of it. In 2025, DEP listed those two supplies as the only sources of city water.

What can differ is the mix. DEP has said that Croton water flows by gravity to lower parts of the Bronx and Manhattan. The rest of the city, including Brooklyn, Queens and Staten Island, gets Catskill/Delaware water. DEP adjusts the blend hour to hour and shows a live map on its Current Water Distribution page. Croton water is filtered first; all of it gets the same chlorine and UV treatment.

The bigger difference is the last stretch of pipe. Water reaches every borough without lead, but a building's service line and plumbing can change what comes out of the tap. That is why lead results vary from home to home, not borough to borough.

What Is in NYC Tap Water: 2025 Test Results

DEP ran more than 332,800 tests on over 24,050 samples from the city's distribution system in 2025. The chart and table show the results most people ask about, compared with the legal limit.

µg/L means micrograms per liter (parts per billion). ng/L means nanograms per liter (parts per trillion). Not detected means below the lab's reporting limit. TTHM and HAA5 limits apply to the running yearly average at each sampling site, so one sample above the number is not a violation. Source: DEP 2025 report, tables on pages 11 to 15.

PFAS in context

NYC took part in EPA's nationwide PFAS monitoring (UCMR 5) from late 2023 through early 2025. None of the 29 PFAS on that list were found in the city's quarterly samples. EPA released the final nationwide results on August 27, 2026. It estimates that about 7.8 percent of US water systems are above the federal limit for PFOA or PFOS.

Violations

New York State's Department of Health recorded no drinking water violations for the NYC system in 2023, 2024 or 2025. The most recent ones were haloacetic acid (HAA5) running averages above the limit in late 2021 and early 2022. The state lists corrective action as taken for both.

Lead: The One NYC Issue Worth Checking

NYC's reservoirs, aqueducts and roughly 7,000 miles of mains do not contain lead. DEP's street-level sampling stations found lead at or near zero in 2025. Lead shows up at the tap when water sits in a lead service line or older plumbing inside a building.

• Old service lines. NYC banned lead service lines in 1961. As of September 2026, DEP records showed about 121,100 known lead or galvanized service lines in the city. Property owners, not the city, own these lines.
• Soft, corrosive water. NYC water is naturally corrosive (it averaged -2.13 on the Langelier index, where anything below zero tends to corrode pipes). That is why DEP adds phosphoric acid to coat pipes and sodium hydroxide to raise the pH.
• The rule is getting stricter. Under EPA's Lead and Copper Rule Improvements, the lead action level drops from 15 to 10 µg/L on November 1, 2027. Homes with lead lines will also be tested with a second, deeper sample. NYC's 2025 result sat right at 10. In 2024, DEP's commissioner at the time told the City Council the city would likely exceed the action level under the new sampling approach. The rule is being challenged in federal court, so dates could change.

Rooftop water tanks

Many taller NYC buildings store water in a rooftop tank before it reaches apartments. The city Health Code requires building owners to have each tank inspected and the water sampled at least once a year by a qualified inspector. Results go to the Health Department by January 15 of the next year. Owners must post a notice telling residents how to see them. You can look up your building's self-reported results by address on the Health Department's tank inspection page.

Chlorine, Not Chloramine

NYC disinfects with free chlorine. Many other large US cities use chloramine instead. This matters for two reasons:

• Taste. Chlorine is the most common reason New Yorkers notice a taste or smell. The 2025 average was 0.6 mg/L, well under the 4 mg/L limit.
• Filtering. Free chlorine is easier to reduce than chloramine. Most activated carbon filters reduce it, including pitcher filters certified to NSF/ANSI 42. An open pitcher left in the fridge also lets some chlorine escape on its own.

When chlorine meets natural organic matter in reservoir water, it forms disinfection byproducts: trihalomethanes (TTHM) and haloacetic acids (HAA5). NYC's 2025 levels were within legal limits. Still, its HAA5 site average of 47 µg/L is closer to the 60 µg/L limit than many people expect. Activated carbon filters can reduce these byproducts. If you notice an unusual color, taste or smell, DEP asks residents to call 311.

Fluoride in NYC Tap Water

Yes, NYC adds fluoride. DEP adds it at 0.7 mg/L as directed by the NYC Department of Health and Mental Hygiene for dental protection. In 2025, 99.3 percent of Catskill/Delaware water and 100 percent of Croton water was fluoridated. The average level was 0.7 mg/L.

In February 2026, a City Council bill (Intro 566) was introduced to end fluoridation. It would offer free fluoride supplements instead. The bill was sent to the Committee on Environmental Protection and Waterfronts and has not passed.

Whether to reduce fluoride at home is a personal choice. Most carbon filters do little for fluoride. Options that do include reverse osmosis, and filters that use activated alumina or bone char. Outside New York, you can check your area with our fluoride zip code lookup.

Hardness and Taste

NYC has very soft water. The 2025 average was 32 mg/L, or about 2 grains per gallon. DEP considers anything up to 3 grains per gallon soft. Most NYC homes do not need a water softener, and soap lathers easily.

The water is also low in dissolved minerals (73 mg/L total dissolved solids on average). That is a big part of why many people like the taste. When there is a taste complaint, it is usually chlorine or a building's own pipes and fixtures.

Do You Need a Water Filter in NYC?

Many New Yorkers drink the tap water unfiltered, and by every legal measure it is safe to do so. People who choose to filter usually have one of four goals. The right filter depends on which one matters to you.

Renters often cannot add under sink or reverse osmosis systems without landlord approval. Pitchers and countertop filters need no plumbing.

Where a Berkey Fits in an NYC Home

A Berkey is a countertop gravity filter. Water drips from an upper chamber through filter elements into a lower chamber, with no plumbing or electricity. In NYC, that suits renters and anyone who wants a large batch of filtered water without changing their sink.

Berkey systems come in two editions. The Black Berkey edition uses Black Berkey Elements, tested by independent laboratories against more than 200 contaminants. The Phoenix edition uses Berkey Phoenix Elements. They are also tested against more than 200 contaminants, and they are certified to NSF/ANSI 42 (chlorine taste and odor) and NSF/ANSI/CAN 372 (lead safe materials).

New Yorkers most often filter for chlorine taste, lead from older plumbing, chlorine byproducts and PFAS. Both editions have independent lab results for all four. Fluoride is handled by the PF-2 add on filters.

NYC's water compared with Berkey lab results

Labs tested water spiked far above NYC levels, and most results fell below the lab's detection limit, so each percentage is a minimum. Full reports: Black Berkey contaminant list and Phoenix contaminant list. PF-2 filters are $103 a pair and last 1,000 gallons or one year, whichever comes first.

Which size fits your household

Prices shown with 2 filter elements. Black Berkey edition systems are available while supplies last (6,000 gallons per pair). Replacement elements for every Berkey are Berkey Phoenix Elements ($120 a pair, 5,500 gallons). NYC kitchen tip: measure the space under your upper cabinets first, and leave room to lift the top chamber off to refill. Not sure which size? Try the system quiz.

Sources

Data checked October 2026. NYC publishes a new water quality report each year; we update this page when it does.