DEP Letter re Hydrilla
environmental
2 pages
Scanned/OCR — text may contain errors
Meeting: portal event 937 (no meeting page on file)
Agenda item: Correspondence — Letter from the NYC Department of Environmental Protection (DEP) regarding the resumption of the Hydrilla project at the New Croton Reservoir.
Environmental review, 2 pages. Attached to agenda item: “Correspondence — Letter from the NYC Department of Environmental Protection (DEP) regarding the resumption of the Hydrilla project at the New Croton Reservoir.” (Text recovered by OCR — may contain errors.)
Retrieved 2026-04-15 from the village's meeting portal.
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Extracted text
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Environmental
Protection
Rohit Aggarwala February 29, 2024
Commissioner
Dear Neighbors:
We are writing to inform you of the resumption of the project at New Croton
Reservoir. In May, the New York City Department of Environmental Protection
(DEP) wili begin the fourth year of a multi-year project to remove Hydrilla
Paul V. Rush, P.E. from the reservoir. Hydrilla is an invasive weed that comes from Asia and
Deputy Commissioner . . . .
Bureau of Water Supply grows aggressively in water, forming dense mats that crowd out native plants,
prush@deo.nyc.gov harm fish habitats, and interfere with boating, fishing, and other recreation.
71 Smith Avenue This di P | Iso h lity b bati h hof
Kingston, New York 12401 is disruptive plant can also harm water quality by exacerbating the growth o
T: (845) 340-7800 algae, and by introducing nutrients that change the taste and smell of water.
F: (845) 334-7175 Hydrilla can also grow thick enough to clog water-supply intakes.
In other words, Hydrilla is a pest that needs to be removed before it affects our
natural resources and drinking water infrastructure.
Hydrilla was first discovered in New Croton Reservoir in 2014. The Hydrilla
infestation started as small patches along the shoreline, but spread quickly to
cover approximately 15 percent of the reservoir.
For several years, DEP has collaborated with New York State and local
communities on a regional effort to remove Hydrilla from the reservoir and the
downstream Croton River. Because you live along the river, you likely received
a notification similar to this each year before the state began its work to
eradicate Hydrilla from the river. That effort is now complete.
Later this spring, DEP will continue to remove the small amount of remaining
Hydrilla from New Croton Reservoir by targeting the weed with an ultra-low
dose of fluridone, a chemical that prevents it from growing. DEP used the same
treatment for the past several years in the reservoir and it was also used by New
York State to safely remove this aquatic plant from the Croton River. Treatment
in the reservoir will happen during summer and early fall, under a permit issued
by the state Department of Environmental Conservation.
DEP chose this method after consulting with a panel of scientists, engineers and
other experts from across the United States. The expert panel studied the
problem at New Croton, reviewed a range of methods to eliminate Hydrilla, and
recommended fluridone as the most safe and effective option. DEP conducted a
pilot study in 2018, 2019, and 2020 by using fluridone in two remote coves in
the reservoir. The study confirmed the treatment would be safe and effective.
The treatment program will be carried out by a licensed applicator. DEP will perform additional
water quality sampling at the reservoir during the treatment season, in close coordination with
the state Department of Environmental Conservation. The use of fluridone in the reservoir will
not affect the Croton River downstream, nor will it affect your ability to use the water for
swimming, fishing, or drinking.
The brand name of the treatment products are included below, along with the water-use
restrictions from their labels:
<1 ppb for
Sonar One 24 hours None None None greenhouse and
nurseries
<1 ppb for
Sonar H4C 24 hours None None None greenhouse and
nurseries
< Ippb for
Sonar Genesis 24 hours None None None greenhouse and
nurseries
If you have any questions, please feel free to call us at (845) 334-7868.
fi Digitally signed by
Michael Michael Usai
. Date: 2024.02.29
U Sal 10:42:42 -05'00'
Michael L. Usai
Deputy Chief
Natural Resources Division
Machine-extracted for search and reference — the original PDF is the authoritative version.