Problems We Found In New York City Drinking Water


Analies Dyjak  |  Policy Nerd
**Updated July 7, 2022 to include current data

For Hydroviv’s assessment of New York City’s drinking water quality issues, we collected water quality test data from the New York City Water Supply System, the Environmental Working Group, and the U.S. Environmental Protection Agency. We cross referenced the city’s water quality data with toxicity studies in scientific and medical literature. The water filters that we sell at Hydroviv are optimized to filter out contaminants that are found in New York City’s drinking water.

Where Does New York City Source Its Drinking Water?

New York City drinking water comes from 19 reservoirs and three controlled lakes, located throughout the Hudson Valley and Catskill Mountain watershed. The New York City Water Supply System delivers 1 billion gallons of drinking water to over 10 million people on a daily basis. New York City’s water supply system is composed of two primary surface water supplies called the Catskill/Delaware and Croton. In 2021, New York City received a blend of drinking water from the Catskill/Delaware and Croton supplies. The Catskill/Delaware provided approximately 88 percent of the water, and approximately 12 percent was supplied by Croton. New York City is known as the gold standard for drinking water treatment, and rightfully so because they are able to serve the largest metropolitan area in the United States. However, none of the pretreatment procedures matter once water hits aging infrastructure.

Lead In New York City’s Drinking Water

Lead enters tap water through old lead service pipes and lead-containing plumbing. Currently, 10% of the water quality samples analyzed by New York City Environmental Protection had lead concentrations over 12 parts per billion (ppb). The highest lead concentration detected from a residential tap was 152 ppb. Environmental Protection Agency, Center for Disease Control, and American Academy of Pediatrics all recognize that there is no safe level of lead for children. To make matters worse, in a city of 8 million people only 375 residential homes were sampled for lead. 24 of those samples exceeded the federal Action Level. The small number of sampling sites is not representative of the actual scope of the lead problem in NYC drinking water. Hydroviv strongly encourages New York City residents to take advantage of the free lead testing program. Under this program, residents can request a free kit to test for lead in their drinking water by calling 311 or visiting

Chromium 6 In New York City's Drinking Water 

Chromium 6 is a highly toxic metal that is currently unregulated by the EPA. Chromium 6 pollution is associated with metal processing, tannery facilities, chromate production, stainless steel welding, and pigment production. The Environmental Working Group tested Chromium 6 levels of water systems nationwide, and New York City's system tested with an average of 41 parts per trillion (ppt), with a maximum level of 57 ppt. The State of California set their own health advisory level of 20 ppt because Chromium 6 is not regulated by the federal government. EPA has acknowledged that Chromium 6 is a known human carcinogen through inhalation. There is strong evidence that chromium 6 is a human carcinogen when ingested as wellChromium 6 exposure is also known to cause multiorgan toxicity such as kidney damage, allergy, and asthma, and is also an endocrine disrupter.

Disinfection Byproducts In New York City's Drinking Water 

New York City Environmental Protection detected significant concentrations of Disinfection Byproducts or DBPs. DBPs are a category of emerging contaminants which means they have been detected in drinking water but the risk to human health is unknown. DBPs are formed when chlorine based disinfectants are routinely added to the water supply to kill bacteria. DBPs are split into two categories: Total Trihalomethanes (TTHMs) and Haloacetic Acids-5 (HAA5). Concentrations for TTHMs were as high as 93 ppb and averaged 56 ppb for HAA5. The EPA standard for TTHMs is 80 ppb.  Concentrations for HAA5 were detected as high as 93 ppb and averaged 65 ppb. The EPA standard for HAA5 is 60 ppb. Regulatory agencies have very little knowledge about the adverse health effects of DBPs and their toxicity. EPA has stated that they have been linked to an increased risk of bladder cancer, as well as kidney, liver, and central nervous system problems. Some disinfection byproducts have almost no toxicity, but others have been associated with cancer, reproductive problems, and developmental issues in laboratory animals. 200 million people in the United States use chlorinated tap water as their primary drinking source, so we take understanding their full health effects very seriously, even if federal agencies fail to regulate all categories.

If you’re interested in learning more about water filters that have been optimized for NYC’s drinking water, feel free to visit to talk to a Water Nerd on our live chat feature or send us an email at

Other Articles We Think You Might Enjoy:
Lead In Drinking Water
5 Things To Know About Chromium 6 In Drinking Water
Disinfection Byproducts: What You Need To Know 

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