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September 16, 2005

Contact: 311

Important Information for Consumers of the New York City Croton Water Supply System

Protecting the Water Supply

Federal law and State regulations require that all New YorkState surface drinking water supply systems filter the waterdelivered to consumers, unless the system can meet strictconditions for “filtration avoidance,” including protection of therelated watershed from where the surface water originates.New York City obtains virtually all of its drinking water fromthree surface water systems originating in upstate watersheds.The systems are known as the Croton, Catskill and Delawaresystems. Since the early 1990s, the City has pursued acomprehensive watershed protection strategy, for its threewater systems, to protect the quality of its drinking water atthe source. The City's program includes, among other things,enforcement of updated watershed rules and regulations, theacquisition of sensitive watershed lands, and the funding ofeconomic and environmental partnerships with watershedcounties, towns and villages to support local efforts aimed atmaintaining or enhancing water quality.

Croton Service Zones
The City is not being required to filter its two largest systems,the Catskill and Delaware systems. For the reasons describedbelow, the City, the State and the United States EnvironmentalProtection Agency have determined that the Croton system(the City’s oldest, supplying about 10% of the City’s dailydrinking water, which in times of drought can supply up to30%) should be filtered.

The Croton System
(Public Water System ID# NY7003666)

Croton system water is not currently filtered, which constitutesa treatment technique violation under federal and Statedrinking water regulations. Due to its unique history andgeography (very different from both the Catskill and Delawaresystems), the Croton system also experiences seasonal waterquality problems associated with elevated color levels, resulting from naturally occurring minerals and organic matterpresent in the water. Although this condition is aesthetic and nothealth-related, it may require the City to discontinue use ofCroton system water while color levels remain elevated, or toblend Croton system water with Catskill system water.


The City’s goal is to ensure that Croton system water is at alltimes protected against microbiological contamination, isaesthetically pleasing, and meets all drinking water qualitystandards. The City is, therefore, proceeding with the designand construction of a filtration plant for Croton system water,pursuant to the terms of a November 1998 federal courtConsent Decree, entered into with the United States and theState of New York. The filtration facility is expected to reducecolor levels in the Croton system water, reduce the risk ofmicrobiological contamination, reduce disinfection by-productlevels and ensure compliance with stricter water qualitystandards.

The Consent Decree, as modified in May 2002, required the Cityto evaluate and choose between three potential sites for thefiltration plant: two in the Bronx, at the Mosholu Golf Course oralong the Harlem River in the vicinity of Fordham Road, and oneat Eastview in Westchester County. The Mosholu Golf Coursesite lies within Van Cortlandt Park, a public park in the Bronx.The City sought State legislation authorizing the alienation ofthe Mosholu Golf Course site for the purpose of constructing,operating and maintaining a Croton filtration plant. In July2003, after passage by the State Legislature, the Governorapproved such legislation and signed it into law. A FinalSupplemental Environmental Impact Statement, comparing thethree sites, was released on June 30, 2004 and it identified theMosholu Golf Course Site as the preferred site for the facility. OnSeptember 28, 2004, the City issued a notice to proceed tobegin the first phase of construction of the filtration plant.

The Law

Until the City begins to filter Croton water, the New York CityDepartment of Environmental Protection is required to send tocustomers of the Croton Water Supply, the followinginformation quarterly:

The United States Environmental Protection Agency (EPA) setsdrinking water standards and has determined that the presence ofmicrobiological contaminants is a health concern at certain levelsof exposure. If water is inadequately treated, microbiologicalcontaminants in that water may cause disease. Diseasesymptoms may include diarrhea, cramps, nausea, and possiblyjaundice, and any associated headaches and fatigue. Thesesymptoms, however, are not just associated with disease-causingorganisms in water, but also may be caused by a number offactors other than your drinking water. EPA has set enforceablerequirements for treating drinking water to reduce the risk ofthese adverse health effects. Treatment such as filtering anddisinfecting the water removes or destroys microbiologicalcontaminants. Drinking water which is treated to meet EPArequirements is associated with little to none of this risk andshould be considered safe.

For More Information

If you have questions about the New York City water supply system or filtration, please write:

New York City Department of Environmental Protection
Bureau of Public Affairs
59-17 Junction Boulevard, Flushing, New York 11373

You can also contact DEP by calling 311, the City’s Non-Emergency Communication Center or visit DEP’s Web site.

More Information

NYC Department of Environmental Protection
Public Affairs

59-17 Junction Boulevard
19th Floor
Flushing, NY 11373

(718) 595-6600