January 3, 2003
Information About Your Drinking Water
individuals living or working in Manhattan and the Southwest Bronx
New York City's Catskill Water Supply System recently violated a drinking
water standard. Although this was not an emergency, and no action is
required on your part, you, as our consumers, have a right to know
the circumstances. Catskill water is distributed in areas of Manhattan
and a small area of the southwest Bronx.
On December 1, 2002, the turbidity of the New York City Catskill Water
Supply at the Kensico Reservoir in Valhalla, New York exceeded 5 nephelometric
turbidity units, at approximately 6:45 a.m. for about 1 hour and 45 minutes.
The actual violation occurred at 8:00 a.m. Turbidity is a measure of water
clarity related to the amount of suspended matter present. The elevated
turbidity was a direct result of operational changes that involved the
opening and closing of valves and gates, which in turn created redirection
of flow and the re-suspension of sediments within water supply facilities.
The turbidity levels returned to normal shortly after the operational
changes were complete, the evening of December 1. As a precaution, chlorine
treatment was increased during the operational changes to enhance the
disinfection of the water. This incidence constitutes a treatment technique
violation of the State Sanitary Code [10 NYCRR Section 5-1.30 (d)]. However,
there is no reason to stop using the water supplied to your home/business
as a result of this violation. Extensive distribution system monitoring
demonstrated that the water supply met all other drinking water quality
standards. While there is no reason to believe this turbidity incident
introduced any microbiological contaminants into the drinking water, the
State and federal drinking water rules require public notification that
includes the following language: Turbidity has no health effects. However,
turbidity can interfere with disinfection and provide a medium for microbial
growth. Turbidity may indicate the presence of disease causing organisms.
These organisms include bacteria, viruses, and parasites which can cause
symptoms such as nausea, cramps, diarrhea, and associated headaches.
For further information, call the New York City Department of Environmental
Protection, Bureau of Public Affairs at (718) 595-6600 or the New York
City Department of Health and Mental Hygiene, Office of Public Health
Engineering at (212) 676-1520. Please share this information with other
people who drink this water.
Public Water System ID#: NY7003493