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NYC Sewage Treatment Plant Discharge UPDATE


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Riverkeeper’s Water Quality Testing Results

Riverkeeper and our science partners sampled the affected area from the Tappan Zee bridge to the Battery on 7/21 and 7/22. In the section of River west of Manhattan, we sampled in a grid pattern to determine the impacts on the Manhattan shoreline as well as mid channel and on the New Jersey side of the River.

Download data from Thursday and Friday’s sampling patrol (PDF).

On Thursday the 21st, the first full day of the discharge resulting from the North River sewage treatment plant shutdown, we found extremely high levels of sewage contamination along the west shore of Manhattan, which at the time of sampling, did not extend north to Yonkers or south of the Battery. Sewage contamination was lower in the middle of the river, and still lower on the New Jersey side. In fact, on the New Jersey side, Enterococcus levels were “acceptable” per EPA guidelines. On Friday the 22nd our sampling indicated similar results, with the highest contamination area being the west side of Manhattan. All sampling occurred before the North River Plant resumed partial operation on the evening of Friday, 7/22. It’s important to note that as of Friday evening, although the contamination pattern was similar and while contamination levels were lower than on the first day of sampling, some areas along the Manhattan shoreline were still very contaminated.

The New York City Department of Environmental Protection (DEP) has posted water quality sampling results for the waters potentially affected by the sewage discharges on the its website at

Riverkeeper’s data adds new and different information to DEP’s data, especially as it relates to the pattern and degree of contamination in the near shore environment.

The highest level of contamination in DEP’s sampling results numbers appears to be 400 Entero cells/100ml; our additional near shore sampling has the highest count from the same day of 104,620 Entero cells/100ml. The DEP’s sampling showed much lower concentrations because the testing is done at beaches and in the center of the river.

Riverkeeper’s sample results reinforce the need for timely public notification about the higher contamination levels in the near shore areas, in order to provide the highest level of protection of public health, since this is where much of the public uses the River.

Riverkeeper is re-sampling Monday the 25th. A revised update will be available late morning, Wednesday the 27th.
Download data from Thursday and Friday’s sampling patrol (PDF)

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