Oxygen Levels in Parts of Great South Bay Seasonally Dip Below Levels Needed to Support Sea-life

Results of Two-Year Study Point to Nitrogen Pollution from Cesspools and Septic Systems as Culprit

Patchogue, NY

Local officials assembled earlier this week to hear the results of a two-year study of the Great South Bay’s oxygen levels and offer support for efforts to reduce nitrogen pollution. New evidence of seasonally low oxygen levels helps to explain previous observations of areas in the bay that are largely devoid of bottom-dwelling sea-life, including hard clams and other shellfish. Already linked to harmful algae blooms and loss of eelgrass, low dissolved oxygen is yet another negative impact of nitrogen pollution, which, in Great South Bay, is largely originating from cesspools and septic systems.

Tristen Tagliaferri, project manager of the study for the United States Geological Survey, pointed out that 24-hour monitoring stations south of Sayville showed sustained periods of very low dissolved oxygen in the summers of 2016 and 2017, with readings sometimes at zero, especially at night. This same area of the bay ranked number one for high nitrogen pollution out of 194 areas studied in Suffolk County, said Ken Zegel, associate public health engineer, who has been involved in an ongoing analysis of Suffolk’s nitrogen pollution problem.

In his remarks, Zegel made reference to another study showing that harmful algae blooms in Suffolk County appear to be increasing in frequency and diversity and “may have reached a level unprecedented elsewhere in the United States.”

In a discussion after the presentations, Brookhaven Supervisor Ed Romaine said that creating a sustained source of funding for wastewater treatment upgrades and other solutions is essential to restore important water bodies like Great South Bay.

Officials from the village of Ocean Beach on Fire Island noted that the village’s wastewater treatment plant has excess capacity and could hook up an additional 700 homes. Ocean Beach is the only place on Fire Island with a sewage treatment plant, which, when properly upgraded, can remove nitrogen better than conventional septic systems and cesspools.

Also on hand were newly elected County Legislator Steven Flotteron, of Islip, his replacement on the Islip Town Board, James P. O’Connor, and Deputy County Executive Peter Scully. Representatives of the Environmental Protection Agency and New York State Department of Environmental Conservation also attended.

The event was organized by The Nature Conservancy, which funded the work with the help of Long Island Community Foundation and other donors, co-sponsors included Citizens Campaign for the Environment, Seatuck Environmental Association, Save the Great South Bay, the Peconic Baykeeper, the South Shore Estuary Reserve Citizens Advisory Committee, and Suffolk County Department of Health Services.

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