Drinking Water FAQs - NYC DEP

Environmental Protection


Water Service Disruptions

Drinking Water FAQs


Our scientists test New York City’s drinking water hundreds of times each day, 365 days a year. They collect samples from the reservoirs, aqueducts, treatment facilities, and 1,000 street-side sampling stations throughout the five boroughs to ensure the tap water is safe, clean and healthy. For information about lead in drinking water, visit Monitoring for Lead.

If you observe a change in your drinking water, please call 311 or file a report online so we can follow up.

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Where does New York City’s drinking water come from?

New York City gets its drinking water from 19 reservoirs and three controlled lakes spread across a nearly 2,000-square-mile watershed. The watershed is located upstate in portions of the Hudson Valley and Catskill Mountains that are as far as 125 miles north of the City.

Learn more about our Water Supply System.

Why is my drinking water brown?

While it is not harmful, residents should not drink obviously discolored water. If you notice brown or discolored water coming from your tap, call 311 or file a report online, so we can follow up.

Recurring Brown Water

Brown or discolored water is often related to plumbing corrosion problems inside buildings and from rusting hot water heaters. If you have an ongoing problem with brown water, it may be due to rusty pipes. You should run your cold water for 2–3 minutes if it has not been used for a long period of time. This will flush the line.

Sudden Brown Water

If your water suddenly looks discolored, it might be because of a disturbance to nearby water mains, including breaks or repairs. This can also happen if there is construction near your building. Additionally, the use of fire hydrants for firefighting can temporarily cause brown water. Because the water mains are pressurized, a disturbance may stir up or resuspend sediments, which causes the water to be discolored. Discoloration is a temporary condition most often from iron and manganese particles that have settled to the bottom of the water pipes buried under the roadways. Any sudden change in the flow of water within the pipes or outside vibration, may loosen or resuspend the brownish/red/orange particles of iron into the water. This temporary problem is generally resolved or reduced when our field staff flush water from nearby hydrants.

If you have brown water due to a recent shut off, visit Water Shut Offs.

Why does my drinking water have a strange taste or odor?

You may, at times, find your water tastes or smells like chlorine. We are required to maintain a chlorine residual in the distribution system to prevent the growth of microorganisms. Chlorine is a very effective disinfectant, and is not considered hazardous or harmful in the amounts used to treat the water supply. New York City water meets all federal and state standards and is safe to drink. Chlorine odors may be more noticeable when the weather is warmer. The most effective way to eliminate or reduce the taste is by leaving a glass or pitcher of your tap water in the refrigerator overnight before drinking. You can also pour water from one container to another about 10 times to reduce the chlorine.

Neighborhoods in New York City receive their drinking water from reservoirs of the Croton System, Catskill System and Delaware System, or often a combination of all three. Water from the Catskill and Delaware Systems and the Croton System can taste different to some of our customers. This is largely because of differences in the geology, soil conditions, and naturally occurring minerals in the watersheds that surround their reservoirs. Visit Current Water Distribution to learn more about the source of your drinking water and why it might taste different.

If you notice that your tap water smells or tastes differently, call 311 or file a report online, so we can follow up.

Why does my drinking water look cloudy?

Air becomes trapped in the water as it makes its long trip from the upstate reservoirs to the city. As a result, bubbles of air can sometimes cause water to appear cloudy or milky. This condition is not a public health concern. The cloudiness is temporary and clears quickly after water flows out of the tap and the extra air is released.

If you notice that your tap water has an unusual cloudy or milky appearance, call 311 or file a report online, so we can follow up.

Is New York City’s drinking water “hard”?

Water dissolves minerals as moves through soil and rocks. “Hardness” is the measure of dissolved minerals, like calcium and magnesium, in drinking water. The higher the content of calcium and magnesium, the “harder” the water. Water with less calcium or magnesium is considered “soft,” which makes it easier to create lather and suds.

New Yorkers receive their tap water from upstate reservoirs in the Catskill/Delaware watershed, the Croton watershed, or a blend of both sources. Water from the Croton watershed is considered “moderately hard,” while water from the Catskill/Delaware watershed is considered “soft” or “slightly hard.” Citywide, the average hardness is about 1.8 grain/gallon (CaCO3). In areas of the City where Catskill/Delaware and Croton Water supplies are blended, the hardness can reach 7 grain/gallon (CaCO3), which is considered “moderately hard.”.

While hard water can leave water spots on shower doors and may affect the efficiency of some equipment, it is safe to drink (in fact, calcium carbonate is the same mineral found in calcium vitamin supplements). If you are operating equipment that uses water, consult the manual to determine the effect, if any, of water hardness.

Visit Current Water Distribution to determine if you are in an area of the city that is receiving moderately hard water.

Common Signs of Hard Water

Hard water can interfere with cleaning tasks like washing dishes, bathing, or doing laundry. Some common signs of hard water include:

White scaly spots on your car after washing it.

Soap scum or film on glass shower doors, shower walls, sinks and faucets, typical “ring around the bathtub.”

Reduced water flow due to hard water deposits inside pipes (scale).

Ways to Reduce the Effects of Hard Water Buildup

Leave a squeegee inside the shower and have each family member squeegee the walls and shower door after each use. This reduces hard-water buildup and a whole lot of scrubbing later on.

Try applying plain white vinegar and lemon juice. These acids help loosen and remove hard water deposits from glass shower enclosures.

If your showerhead plugs up from hardness, fill a sandwich bag with vinegar and use a rubber band to fasten the bag around your showerhead. Leave it overnight.

Pour a cup of white vinegar in the toilet bowl and leave it there overnight. Flush in the morning.

Reduce the temperature of your hot water to 60°C or lower to decrease the build-up of scale.

Follow the manufacturer’s instructions for any appliances that use water.

Does New York City drinking water contain fluoride?

Yes, New York City drinking water contains fluoride. In accordance with Article 141.05 of the New York City Health Code, we add a fluoride compound that provides the water supply with a concentration of about 0.8 mg/L of the fluoride ion. Fluoridation began in 1966.