United States
Environmental Protection
Agency
Total Maximum Daily Loads
TMDLs
and New York
TMDL at a Glance
Long Island Sound Nitrogen TMDL
(approved April 2001)
www.longislandsoundstudY.net/pubs/reports/Tmcll.pclf
Lessons in Innovation and Collaboration
Is it possible to make significant reductions in pollution while saving tax payers a large
amount of money? Stakeholders in the Long Island Sound are demonstrating that it
is possible, using innovative approaches and multi-state collaboration. The Sound's
watershed is home to almost 9 million people with an area that includes most of
Connecticut and portions of New York, Rhode Island, New Hampshire, Massachusetts,
and Vermont. Pollutant sources associated with increased urbanization, including sewage
treatment plants and stormwater runoff, have discharged excessive levels of nitrogen to
the Sound leading to increased algal blooms and decreased dissolved oxygen (DO) levels.
As a result of eutrophication and hypoxia, large areas in the western portion of the
Sound can not support aquatic life, recreation, and other important uses.
Factors causing impairment
Aesthetics, fishing, and water contact recreation
designated uses impaired due to reduced dissolved
oxygen levels and excessive algal blooms
Sources contributing to impairment
Sewage treatment plants, combined sewer overflows,
agricultural runoff, urban runoff, and atmospheric
deposition
Restoration options
Attain a 58.5 percent reduction in nitrogen discharges
to Long Island Sound from Connecticut and New York.
Upgrade sewage treatments plants with nitrogen
removal technologies, implement a nitrogen credit
trading program, issue bubble permits to sewage
treatment plants, reduce atmospheric deposition by
controlling nitrous oxide emissions from vehicles,
control polluted runoff through stormwater best
management practices and growth management
a Stakeholder involvement
Long Island Sound Study partners, including state
and federal agencies, private organizations, and
educational institutions; Connecticut Department
of Environmental Protection; New York State
Department of Environmental Conservation;
municipalities along the Sound's shore throughout
New York; municipalities in Connecticut; New England
Interstate Water Pollution Control Commission;
U.S. Environmental Protection Agency
Status of waternody
Nitrogen loading to Long Island Sound reduced by
25 percent from the adjusted 1990 baseline load.
Benefits to stakeholders
Reduced nitrogen loads, cost savings, funding,
partnerships
To address the water quality problems in the Long Island Sound, EPA created the
Long Island Sound Study (LISS) in partnership with the Connecticut Department
of Environmental Protection (CTDEP) and the New York State Department of
Environmental Conservation (NYSDEC). Work conducted through the LISS
helped to support the development of the nitrogen TMDL for the Long Island
Sound. Innovative implementation strategies, including a nitrogen credit trading
program for sewage treatment plants (STPs) in Connecticut and bubble permits
for STPs in New York, have not only led to significant nitrogen reductions in Long
Island Sound, but also significant cost savings.
How are TMDLs at work in Long Island Sound?
Years of research, monitoring, and modeling helped the LISS to identify nitrogen
sources in the Long Island Sound and levels of nitrogen control necessary to
improve DO levels and meet water quality standards. The analysis conducted by
the LISS led to the adoption of a 58.5 percent nitrogen reduction target to reduce
the extent and duration of hypoxic conditions in the Long Island Sound. Through
the TMDL development process, CTDEP and NYSDEC were able to incorporate
the 58.5 percent nitrogen reduction target into a regulatory and legal framework.
The Clean Water Act (CWA) requires implementation of pollutant load reductions
through point source permits issued under the National Pollutant Discharge
Elimination System (NPDES) Program. As a result, CTDEP and NYSDEC point
source permit writers must develop permit requirements to implement the
nitrogen reduction target. Without the TMDL, the nutrient reduction target
established by the LISS after years of research and analysis would not have an
enforceable implementation mechanism. In addition, the nitrogen TMDL for the
Long Island Sound recommends flexible, innovative implementation approaches,
including nitrogen trading.
What is a total maximum daily load (TMDL)?
It is a study or analysis that calculates the maximum amount of a pollutant that a waterbody can receive and still meet
water quality standards. The TMDL establishes a pollutant budget and then allocates portions of the overall budget to
the pollutant's sources. For more information on TMDLs, visit EPA's website at www.epa.gov/owow/tmdl.
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What is the current status of the Long Island
Sound as a result of the TMDL process?
Increased DO levels, resulting from reduced nitrogen
loads, should decrease the number of days and the extent
of hypoxia in the Sound during the critical summer
months. According to the LISS environmental indicators,
the extent of hypoxic conditions during 2007 was 162
square miles; the seventh least severe year since 1991.
Hypoxia in the bottom waters lasted 58 days, one day
above the average from 1987 through 2007. As discussed
in the final TMDL report, attaining the DO water quality
standards will require further nitrogen reductions from
both in-basin and out-of-basin sources.
How did local stakeholders benefit from the
TMDL process?
Implementing innovative nitrogen reduction approaches,
including nitrogen trading and nitrogen load reallocation
under bubble permits, has helped point sources in
Connecticut and New York make significant progress
toward achieving the 58.5 percent nitrogen reduction
goal for 2014. It is anticipated that these improvements,
coupled with nitrogen reductions from out-of-basin
sources, will improve DO levels and reduce hypoxic
conditions in Long Island Sound over time.
In addition to water quality benefits, the TMDL process
and the innovative approaches for achieving nitrogen load
reductions promoted through the TMDL have benefitted
stakeholders in several ways.
O Increased cost savings while achieving nitrogen
reductions. Upgrading STPs is an expensive endeavor.
During 2003-2007, Connecticut has upgraded 19
STPs for a cost of $56.5 million. However, through
Connecticut's Nitrogen Credit Exchange Program, the
upgrades generated $10.5 million worth of nitrogen
credits in five years. This program is expected to
save between $200 and $400 million in wastewater
treatment construction costs over the next ten years.
Figure 1 shows an aeration tank installed at the
Stratford (Connecticut) STP as part of the facility's
upgrade to implement a biological nutrient removal
technique. New York's bubble permits for management
zones are expected to save money as well. For example,
New York City is expected to save $660 million in STP
upgrade costs.
Figure 1. Stratford aeration tank.
Improved water quality for recreation activities
important to the regional economy. Based on a 1992
study, recreational activities in the Long Island Sound
are estimated to contribute an annual revenue of more
than $8 billion (inflation adjusted) to the regional
economy. As water quality improves, tourists are
more likely to use the Long Island for swimming and
boating, generating more cash flow.
Increased access to funding. LISS partner agencies
and organizations contribute funding to support
implementation activities that will achieve nutrient
reductions and achieve DO water quality standards
in the Sound. Connecticut has provided hundreds
of millions of dollars in grants and loans through its
Clean Water Fund to implement nitrogen reductions.
New York targeted $270 million in grant assistance for
Long Island Sound in the 1996 Clean Air/Clean Water
Bond Act.
Increased local, state, and regional partnerships.
The LISS is a highly effective bi-state partnership
that involves state and federal agencies, concerned
organizations, and individuals. Through the TMDL
process, the network of partnerships has grown.
Individual STPs collaborate with the states and other
STPs to achieve nitrogen load reductions. States north
of Connecticut collaborate to establish out-of-basin
nitrogen reduction targets and identify strategies
to achieve those targets. The public participation
processes for the TMDL process and the subsequent
permitting activities also generate partnerships within
the Long Island Sound watershed.
For more information on the Long Island Sound nitrogen TMDL, contact
Mark Parker, Connecticut Department of Environmental Protection, mark.parker@ct.gov, (860) 424-3276
Sarah Deonarine, New York State Department of Environmental Conservation,
sndeonar@gw.dec.state.ny.us, (631) 444-0467
For more information on the Connecticut TMDL Program,
visit www.ct.gov/dep/cwp/view.asp?a=2719&q=325604&depNav_GID=1654
For more information on the New York TMDL Program, visit www.dec.ny.gov/chemical/31290.html
&ER&
December 2009
EPA841-F-09-002D
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