Subject: Manhasset Bay Protection Committee electronic newsletter –
The Manhasset Bay Protection Committee is releasing the recently
completed Water Quality Analysis Report which covers data collected
during the summers of 2009 through 2015. While seven years of data
is a long period of time to look at, it was still too short a time
span to detect any trends. The report and supporting documents will
be posted to the Committee’s “Water Quality Data” page at
Background of the Report
Manhasset Bay Protection Committee, working with the Town of North
Hempstead, contracted with the environmental engineering firm Fuss &
O’Neill, Inc. for this work. The Committee requested a study which
compiled seven years of bacteria and water quality data and
connected it with weather and environmental events. The New York
State Department of Health maintains a safe swimming standard based
on how much bacteria is found in the water. The report also looked
at dissolved oxygen data collected by the Interstate Environmental
Commission. Dissolved oxygen is important for marine life to
survive and can be low during the summer when there are not many
storms to mix the water.
Manhasset Bay is generally safe for swimming (where allowed),
except within a day or two of rainfall.
significantly impacts water quality.
Rainfall acts the fastest (same day) and has the largest impact
on water quality near the densest development (Port Washington
peninsula), where many stormwater outfalls are located. In
contrast, the sampling stations on the western shore (Great Neck
peninsula) and in the middle of the Bay show correlations with
prior day rainfall. These findings are consistent with what is
seen in other bays and harbors.
The highest bacteria concentrations are on the eastern side of
the Bay. At times, these bacteria counts are high even without
rain, indicating that a factor other than stormwater may be
affecting water quality here. Despite this, water quality at
these beaches still meets the New York State swimming standards
when there has not been rain.
Dissolved oxygen (DO) concentrations are lowest at the head of
the Bay (near Manhasset). This is consistent with conditions of
shallower depth and less mixing with ocean waters.
Despite the many major
storms (Super Storm Sandy and Hurricane Irene) and growth of
population, no increase in bacteria was evident in Manhasset Bay.
Further evidence of improved water quality is the abundant wildlife
that have returned to the area, like the Harbor Seal pictured below
who visited Town Dock on November 6, 2017(photo credit: Jennifer
Wilson-Pines). Water quality is expected to continue to recover,
especially with the continued diligence of the residents that share
the watershed (for more on watersheds, visit:
Sampling of water quality parameters (DO, salinity, pH) should
be taken at the same time and same locations as bacteria
samples. This would allow for expansion of the data set.
Investigation of stormwater outfalls discharging during dry
weather would provide information on potential bacteria sources.
Targeted sampling of stormwater outfalls during wet weather for
parameters indicative of sewage (e.g., pharmaceuticals) would
help identify non-stormwater sources of bacteria.
Use of DNA-based testing could allow for confirmation or
elimination of suspected human sources in areas where dry
weather bacteria concentrations remain elevated.
Electronically mapping the location of all outfalls within the
Bay, including information on ownership, size, and condition,
would provide a useful resource.
Hydrodynamics within the Bay could be investigated to understand
how tides and discharges interact to influence water quality.
Tidal phase (i.e., flood, slack, ebb) could be included as an
observation during water quality monitoring.
Where Do We Go From Here
Bay is a vital resource which impacts the local and regional economy
and the Manhasset Bay Protection Committee remains committed to
implementing projects and activities that facilitate an improvement
in water quality. Many of the key conclusions of this report, such
as the improvement in water quality from more developed areas to
less developed areas and the link between bacteria concentrations
and stormwater runoff, are not a surprise and the reason we are
already working in this area. Additionally, key recommendations of
this report, such as watershed-wide
planning and DNA-based testing, are already being pursued by the
Committee. Other initiatives aimed at improving water quality
include “Get Pumped LI!” and the Long Island Nitrogen Action Plan.
However, despite all this great work, water quality cannot continue
to improve without the help of everyone. Simple actions, such as
picking up after pets, not over-fertilizing lawns, and keeping
everything but stormwater out of storm drains, will make a big
difference.The next report, due in 2019, will cover water quality
data collected in 2016 and 2017.
The Manhasset Bay Protection Committee is an inter-municipal
organization focused on addressing water quality and coastal issues
in Manhasset Bay with a coordinated, watershed-level approach. The
Committee has 15 member municipalities: Nassau County, the Town of
North Hempstead, and 13 Villages who all voluntarily entered into an
inter-municipal agreement. The Committee’s goals are to protect,
restore, and enhance Manhasset Bay so as to insure a healthy and
diverse marine ecosystem while balancing and maintaining
recreational and commercial uses. Tasks that help toward these goals
include the annual water quality monitoring and regular assessment
of Manhasset Bay.
Manhasset Bay is one of the westernmost estuarine embayments of the
north shore of Long Island, NY. The Bay is, therefore, influenced by
activities in and around New York City and Long Island Sound, as
well as its own watershed. According to the New York State
Department of Environmental Conservation’s (the State regulatory
agency concerned with environmental issues both on the land and in
the water) Priority Waterbodies List, Manhasset Bay is impaired by
pathogens (as indicated by the bacteria fecal coliform and
enterococcus) from stormwater runoff.
Manhasset Bay is a vital resource which impacts the local and
regional economy. The Manhasset Bay Protection Committee remains
committed to implementing projects and activities that facilitate an
improvement in water quality toward the swimmable, fishable goals of
the Clean Water Act.
for How Everyone Can Help:
Listed below are some examples of simple changes to everyday
activities that will have a positive impact on Manhasset Bay, even
in areas seemingly far from the Bay.
Clean up after pets: dog (and even cat) waste that is left on the
ground can be picked up by rain water and transported to Manhasset
Bay, increasing bacteria counts.
Do not put anything down a storm drain, ever. This water is not
treated, but instead flows directly to Manhasset Bay. As a
reminder, look for medallions like the one pictured at right on
Clean up spills of fertilizer and pesticides: like pet waste, these
spills can be picked up by rain water and transported to Manhasset
Bay, where they can have adverse impacts on water quality.
If you have a cesspool or septic tank, get pumped out regularly.
for more information.
Don’t feed ducks, geese, or other birds: there is a bounty of food
that nature provides which is better than anything people feed them
(and human food can actually be harmful). Also, feeding birds tends
to concentrate them in an area, leading to more bacteria entering
the water from their droppings.
Don’t flush anything unless it passed through you first, with the
exception of toilet paper. Foreign objects, even those that claim to
be “flushable,” can clog sewer and cesspool systems, causing leaks
of untreated or poorly treated sewage.
Don’t fertilize before a rain storm and consider getting your lawn
tested to learn how much fertilizer it needs. Also consider leaving
grass clippings in place after mowing: they break down quickly and
naturally fertilize the soil.
Do not pour grease and oil down the sink and be sure to report to
the Town or Village if you see anyone doing just that. Similar to
flushing the unflushables, grease and oil cause clogs and are often
the cause of sewage spills.
Connecting downspouts to the sewer system is illegal. Remove these
hook-ups and notify the Town or Village where you live if you see
someone else doing this. Consider alternatives, such as rain
gardens, for your downspout discharge.
Volunteer for a beach clean-up! Trash un-intentionally gets blown
away and ends up in Manhasset Bay. Help combat this problem at the
source by properly disposing of your garbage and on the beach by
for more information.
Committee members are:
Town of North Hempstead
Port Washington North
Thank you for reading this first installment.
We want to hear from you!
Please send us any comments, questions, etc. on this newsletter or
15 Vanderventer Avenue, Port Washington, NY 11050
Copyright 2018 Manhasset Bay Protection Committee