Riverkeeper, New York's clean water advocate, was out last Friday, November 2nd, to sample the waters after Hurricane Sandy. They just published the results of these tests. They show that the Gowanus Canal had the highest sewage level by far. Though we all know that Combines Sewer Overflow is dumped into the canal during heavy rains, it is important to note that Hurricane Sandy, though destructive, was not significant rain event. In comparison to the Gowanus findings after the storm, even Newtown Creek's numbers came in fairly low.
Riverkeeper will be out again on Friday, November 9th to take additional samples.
four days after Superstorm Sandy
Last Friday, Riverkeeper conducted our first patrol of New York Harbor since Sandy. The water quality conditions "looked" really good, better than average, at all sample sites except the Gowanus Canal. There, the water was grey and opaque, which is often the case when high levels of sewage contamination are present.
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| A Combined Sewer Overflow (CSO) discharge pipe next to our sampling site in the Gowanus Canal |
Sewage contamination levels at 6 of our standard sampling sites on 11/2/12
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When compared to our historic sampling data for these same locations it’s pretty clear that although we expect that combined sewer overflows (CSOs) were discharging, the extra volume from storm flooding (dilution) resulted in temporarily lower sewage concentrations than we have often observed at these locations, especially after storms. We measure much worse regional contamination during run-of-the-mill summer rainstorms than we found after Sandy.
Historic contamination levels at these sites 2006 – 2011
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The three very high tides which occurred during the storm (Monday morning through Tuesday midday) brought unimaginable amounts of clean sea water into New York Harbor and appear to have “flushed” the entire harbor, including the sewage contamination released by CSOs and any pump station and sewer plant failures that occurred. The extreme contamination in the Gowanus Canal is probably due to additional, perhaps ongoing, sewage discharges from CSOs or bypasses into the Canal continuing after the tidal flooding ended.
Riverkeeper is also concerned about the chemical, petroleum and floatable pollution (such as plastics) that undoubtedly entered the river, harbor and ocean as a result of the tidal flooding and subsequent “flush.”
Learn more about Riverkeeper’s Water Quality Program:
- View other monthly water quality reports, June 2010 to present.
- View historic sampling data sorted historically by individual sampling location.
