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Progress in Restoring Long Island Sound

Spring 2014 Issue

I view Long Island Sound as a national treasure. As many Long Islanders know, however, hypoxia (a condition that occurs when nutrients such as nitrogen cause the water's oxygen level to become so low that aquatic life is harmed), has been a major issue in portions of Long Island Sound. In 2004, the US Environmental Protection Agency (USEPA), Connecticut and New York completed a technical plan - the Long Island Sound Dissolved Oxygen TMDL (total maximum daily load) - to address hypoxia by significantly reducing the amount of nitrogen entering the Sound from wastewater treatment plants. Eighty-five percent of the goals outlined in the TMDL were targeted to be met by the end of 2014. New York State, with great leadership by the Sound communities, is making substantial progress on implementing this plan.

As of 2012, New York had achieved reduced discharges of nitrogen equal to 64 percent of the overall goal. As many large scale projects are now being completed, these reductions are accelerating dramatically. New York expects to achieve the scheduled 85 percent nitrogen discharge reduction goal by the end of 2014 (it might well exceed this goal), and meet 100 percent of the goal by the end of 2017.

The majority of the reductions from New York result from treatment upgrades at New York City wastewater treatment plants. As of 2012, New York City reduced its nitrogen discharges by over 50 percent. The NYS Department of Environmental Conservation's (NYSDEC) projection is that New York City will achieve 90 percent of its required reductions by 2014 and 100 percent by 2017.

Westchester County is implementing a program to meet its nitrogen reduction allocation by August 1, 2017. Significant progress has already been made toward that goal, including the first phase of upgrades for the Mamaroneck wastewater treatment plant which was completed in July 2013. The New Rochelle wastewater treatment plant is scheduled to be completed by July 2014, while the North Castle treatment upgrade has already been completed. It is possible that these upgrades alone will achieve the nitrogen reduction goals for Westchester; but if not, Westchester County is set to undertake further efforts to remove any remaining increment of nitrogen by 2017.

Meanwhile, all wastewater treatment plants in Nassau County have been upgraded and are meeting their August 2014 Long Island Sound TMDL permit limits. The consolidated Great Neck wastewater treatment plant, which has reached substantial completion two months ago, has been fine tuning the denitrification process in their oxidation ditch and reported full compliance this month with their 2014 TMDL limit. In addition, all Suffolk County wastewater treatment plants either have been upgraded and are meeting their permit limits, or are under construction and on target to be in conformity with the TMDL limit by August 1, 2014.

New York's work on Long Island Sound wastewater treatment plants, at an estimated cost of over $2 billion, is impressive and highlights an effective local and state partnership. Even with the hard-pressed circumstances of government finances, projects are being built and the nitrogen levels in the Sound are falling. The NYSDEC has been and will continue to be diligent in efforts to improve and protect the Sound by other efforts including addressing polluted runoff, reducing emissions that cause the atmospheric deposition of nitrogen, implementing comprehensive marine sanitation no-discharge zones, and habitat restoration.


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