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High Quality NYC Tap Water Receives New Filtration Waiver

December 28, 2017

10-year waiver for Catskill and Delaware water supplies acknowledges high quality of NYC water and supports affordability; NYC one of only four large U.S. cities with waiver; DEP to commit $1 billion over next decade to continue watershed protection efforts

Photos of the NYC Water Supply System can be found on DEP’s Flickr Page

NEW YORK—The New York City Department of Environmental Protection today announced that it received a 10-year waiver to continue delivering unfiltered drinking water from its Catskill and Delaware water supply systems. The waiver, known as a Filtration Avoidance Determination (FAD), was released today by the New York State Department of Health (DOH). The City will commit an estimated $1 billion over the next decade to comply with the FAD by administering programs that protect the upstate reservoirs and the vast watershed lands that surround them.

“This confirms what every New Yorker knows: we have some of the cleanest and best tap water in the world,” said Mayor de Blasio. “I would like to thank the 6,000 city employees who made this possible by working tirelessly to operate, maintain and protect our water sources.”

“The renewal of our filtration waiver underscores that New York City has some of the highest quality and best protected drinking water in the world,” DEP Commissioner Vincent Sapienza said. “But protecting our water at its source in the Catskill Mountains does not happen by accident. The programs outlined in the FAD are based on decades of scientific research and investment. Since the City received its first filtration waiver in the early 1990s we have protected open space around our reservoirs, invested in wastewater upgrades, forged partnerships with watershed farmers, and focused considerable attention on the forests, streams and wetlands that comprise the natural infrastructure of our water supply. Importantly, none of this work could succeed without the vital local partners who administer our watershed protection programs. New Yorkers owe their gratitude to the nonprofits, government agencies and other watershed-based partners who carry out this work as we push toward the common goal of protecting the largest municipal water supply in the United States.”

“New York City tap water is safe, healthy, and delicious,” said Health Commissioner Dr. Mary T. Bassett. “The City’s maintenance of our water supply earns it the moniker ‘the champagne of tap water’ and ‘the healthiest thirst quencher.’”

Over the past 25 years, the City’s watershed protection programs have been praised as a worldwide model for protecting the quality of drinking water at its source. These efforts, paired with a robust program of water quality testing and infrastructure improvements, have allowed the City to avoid the construction of a costly filtration plant for its Catskill and Delaware supplies. Such a facility is estimated to cost more than $10 billion to construct, upwards of $100 million to operate each year, and would be the largest public works project in the history of the City.

New York City’s water supply is comprised of three distinct systems – Croton, Catskill and Delaware. Their reservoirs work in concert to meet the demand of 8.5 million consumers in the five boroughs of New York City, and another 1 million people in four counties north of the City. The system delivers about 1.1 billion gallons of water each day.

The Catskill and Delaware systems comprise the largest unfiltered water supply in the United States, delivering about 90 percent of New York City’s water on a typical day. Millions of laboratory tests in the City and the watershed show that water from these two systems continues to meet the stringent criteria to avoid filtration. The Croton System became a filtered supply in 2015. It supplies about 10 percent of the City’s water.

For decades the City has implemented a strategy of source-water protection to maintain the high quality of water in its reservoirs. The science-based programs in the FAD are rooted in the premise that it is most cost effective and environmentally sound to protect the quality of water at its natural source. DEP’s programs in the watershed have become a national and international model for protecting water at its source. Each year, water utility managers and public health professionals come from around the globe to study the City’s watershed programs. This year alone DEP has welcomed visitors from Australia, Chile, China, Colombia, India, Singapore, the United Kingdom and others that aimed to solve water-quality challenges by replicating part of New York City’s protection programs.

A key element of New York City’s success in watershed protection has been the development of strong relationships with watershed communities, locally based organizations, environmental groups, and federal, state and local government agencies. While the watershed protection programs are fully funded by City water rate payers, most of them are administered by watershed-based entities that partner with DEP to protect the water supply from environmental degradation or potential sources of contamination.

Including the new FAD, the City has committed more than $2.7 billion toward its watershed protection programs since 1993, when the U.S. Environmental Protection Agency first issued the City a waiver from the federal requirement to filter tap water that comes from surface sources such as reservoirs. A 1997 memorandum of agreement allowed the City to move ahead with three central components of source-water protection: acquisition of vacant land in the watershed to minimize pollution resulting from widespread development in areas near reservoirs and the streams that feed them; regulatory controls over new development to ensure building projects were protective of water quality; and a series of City-funded partnership programs to address existing and potential sources of water pollution. This multi-pronged approach has provided flexibility to counter evolving threats such as climate change, and the agility to reallocate resources after large storms or to meet other unforeseen needs. 

DEP’s source-water protection initiatives and achievements have included:

  • DEP has administered a successful land acquisition program that has preserved 147,221 acres of land through fee-simple purchases or conservation easements since 1997. These lands are purchased at fair-market value, and only from willing sellers. In addition, the City already owned nearly 45,000 acres of land surrounding its reservoirs, the State of New York owns and permanently protects 210,000 acres as parkland or forestland, and other entities own and protect nearly 25,000 acres as parkland or forestland. Nearly 40 percent of the watershed is now preserved as open space.
  • The nonprofit Watershed Agricultural Council, one of the City’s watershed partners, has completed more than 450 “whole farm” plans that incorporate pollution prevention into the business operations of local farms. Those plans have included the installation of more than 7,400 best management practices to control runoff from farms and minimized the amount of nutrients entering local waterbodies.
  • DEP has completed upgrades on all private and public wastewater treatment plants in the Catskill-Delaware watershed, including upgrades to five City-owned treatment plants and dozens not owned by the City.
  • The Catskill Watershed Corporation (CWC), another key partner organization funded by the City, has invested in the repair of failing septic systems across the watershed, with more than 5,000 repairs completed to date. CWC also works with communities to construct stormwater controls that protect water quality.
  • DEP has implemented a comprehensive stream management program to restore the natural stability and flood resiliency of streams that feed the reservoir system. To date, the program has funded 364 project to restore stream stability and streamside vegetation along 41.2 miles of waterways in the Catskills.
  • DEP developed a comprehensive plan to manage the forests on City-owned lands, which act as nature’s filter by soaking up nutrients and preventing erosion.
  • DEP administers a regulatory program to review and approve new development proposals in the watershed. All proposals must comply with standards designed to protect watershed streams and reservoirs, especially as they relate to wastewater and stormwater. Over the past 20 years DEP has reviewed more than 20,000 applications, approving 99.95 percent of them.
  • DEP maintains a robust water-quality monitoring program that tests New York City’s drinking water at more than 475 sites in the watershed and from approximately 1,000 street-side sampling stations in the five boroughs. Scientists collect about 52,000 samples each year, and perform nearly 640,000 analyses on those samples. In addition, a growing network of robotic monitoring equipment measured the City’s water quality about 1.2 million times each year. These laboratory tests ensure the City’s water meets and exceeds all regulations, and they also provide data to show the success of DEP’s watershed protection efforts over time.
  • DEP has worked in partnership with local communities to identify and invest in projects that mitigate flooding in watershed communities. These projects, which protect water quality by minimizing the amount of debris that gets washed into streams during floods, have included the rightsizing of infrastructure such as bridges and culverts, and the relocation of key community facilities to lands that are outside of floodplains.
  • Balancing the goals of watershed protection with the needs of the region, DEP has also opened 135,000 acres of City-owned property for recreation throughout the watershed. These lands and waters are open for fishing, hiking and other forms of low-impact recreation that support the tourism and outdoor recreation economies of the region.
  • CWC also administers the Catskills Fund for the Future, which was established with money from the City. The local development fund provides grants and low-interest loans to support watershed businesses for job growth and retention. The fund has yielded approximately $90 million in direct and leveraged investments in the Catskills, creating or retaining more than 4,900 jobs.

The new FAD issued by DOH today requires the City to continue these core programs. It also requires some new or additional investments in the years ahead. They include:

  • Expanding the small-business septic program in the west-of-Hudson watershed.
  • Expediting the development of a community wastewater facility for the hamlet of Shokan near Ashokan Reservoir.
  • The implementation of additional best-management practices on watershed farms.
  • Protecting additional streamside lands through the Conservation Reserve Enhancement Program and the Streamside Acquisition Program.
  • The National Academies of Sciences, Engineering and Medicine will assemble a panel of experts to review New York City’s source water protection programs. The expert panel is expected to begin its work in 2018. 

More information about the FAD can be found on the DOH website at the following address:

More information about New York City’s watershed protection programs can be found:

The FAD applies to New York City’s six large reservoirs in the Catskill Mountains – Ashokan, Schoharie, Rondout, Neversink, Pepacton and Cannonsville – which deliver their water to the City through two large aqueducts. Some FAD programs also apply to a handful of reservoirs east of the Hudson River – including Cross River, Croton Falls, Hillview, Kensico and West Branch. Some of these reservoirs receive water from the Catskills and convey it as part of the unfiltered supply, or they have infrastructure that can pump water into the unfiltered supply during times of drought.

DEP manages New York City’s water supply, providing more than 1 billion gallons of high-quality water each day to more than 9.5 million New Yorkers. This includes more than 70 upstate communities and institutions in Ulster, Orange, Putnam and Westchester counties who consume an average of 110 million total gallons of drinking water daily from New York City’s water supply system. This water comes from the Catskill, Delaware, and Croton watersheds that extend more than 125 miles from the City, and the system comprises 19 reservoirs, three controlled lakes, and numerous tunnels and aqueducts. DEP has nearly 6,000 employees, including almost 1,000 scientists, engineers, surveyors, watershed maintainers and other professionals in the watershed. In addition to its $70 million payroll and $166 million in annual taxes paid in upstate counties, DEP has invested more than $1.7 billion in watershed protection programs—including partnership organizations such as the Catskill Watershed Corporation and the Watershed Agricultural Council—that support sustainable farming practices, environmentally sensitive economic development, and local economic opportunity. In addition, DEP has a robust capital program with a planned $20.7 billion in investments planned for the next 10 years that will create up to 3,000 construction-related jobs per year. For more information, visit, like us on Facebook at, or follow us on Twitter at

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