New info provided by Phillip Mesegaas at Riverkeeper. Our thanks again to him and the others who have made an effort to keep the human-powered boating community informed.
The DEP has posted water quality sampling results for 7/21 for the waters potentially affected by the sewage discharges related to the fire and temporary closure of the North River sewage treatment plant, on the DEP website at http://www.nyc.gov/html/dep/html/news/north_river_wastewater_treatment_plant_fire.shtml
Riverkeeper and our science partners also sampled on 7/21 from the Tappan Zee bridge to the Battery. 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.
Overview:
1) Our 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.
2) Our data shows that the NJ shoreline, mid-channel and Manhattan shoreline data are very different. It matters where one samples and our data shows extreme pollution levels along the NY shoreline, based on our sampling results from nearshore sampling locations. To the best of our knowledge, DEP did not take samples in the nearshore area.
3) For protecting public health it is important that people are aware of the potentially high levels of pollution in the shoreline environment because that is where people generally contact the water.
4) 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.
Details:
This difference between Riverkeeper and DEP data has very important implications regarding how samples were collected, and what is sufficient for proper notification and protection of public health. Note below the patterns seen in Riverkeeper's data when sorted by sampling location. While we don't know the exact details of where in the river the DEP collected, we think that differences in sampling locations likely accounts for the discrepancy (given the patterns in our data) and this is VERY IMPORTANT for the public's understanding of this event.
Note: for salt or brackish water the federal guideline for unacceptable water quality is a single sample value above 104 Enterococcus per 100/ml.
If we had conducted the survey by sampling ONLY close to the western shoreline (NJ), our data shows the following:
Englewood Boat Basin <10 Enterococcus per 100/ml
Edgewater Marina 31
Weehawken <10
Castle Point (NJ) <10
If we had sampled ONLY down the middle of the river our data shows the following:
Tappan Zee Mid River <10 Enterococcus per 100/ml
Yonkers Mid River <10
GWB Mid River 313
125th St Mid River 74
79th St Mid River Duplicate samples 132 and 161
Battery Mid River 10
In contrast, our sampling numbers from the eastern shoreline (Manhattan) indicates intense near shore contamination of the near shore area:
Hudson at Yonkers where Sawmill R. enters <10 Enterococcus per 100/ml
Westchester/Yonkers Sewage Treatment plant outfall <10
Dykeman Street at public pier >24,196
125th Street Pier (1/10 dilution maxed out at >24,196) 1/100 dilution = 104,620
79th St Boat Basin entrance 1722
Pier 96 (kayaking area) 12,033
Englewood Boat Basin <10 Enterococcus per 100/ml
Edgewater Marina 31
Weehawken <10
Castle Point (NJ) <10
If we had sampled ONLY down the middle of the river our data shows the following:
Tappan Zee Mid River <10 Enterococcus per 100/ml
Yonkers Mid River <10
GWB Mid River 313
125th St Mid River 74
79th St Mid River Duplicate samples 132 and 161
Battery Mid River 10
In contrast, our sampling numbers from the eastern shoreline (Manhattan) indicates intense near shore contamination of the near shore area:
Hudson at Yonkers where Sawmill R. enters <10 Enterococcus per 100/ml
Westchester/Yonkers Sewage Treatment plant outfall <10
Dykeman Street at public pier >24,196
125th Street Pier (1/10 dilution maxed out at >24,196) 1/100 dilution = 104,620
79th St Boat Basin entrance 1722
Pier 96 (kayaking area) 12,033
Conclusions:
1) It matters how/where one samples. On the 21st, mid-channel samples alone would miss most of the contamination (since overflow points were mostly in the Manhattan near shore environment). Near shore sampling is important to proper notification and protection of public health because people are more likely to be coming into contact with the water near shore. We saw people in the water on the west side of Manhattan on both the 21st and 22nd).
2) Our data shows that while many sites far removed from the point sources (pipes used for bypass) did not show a large signal, sites that are in close proximity to the discharging pipes (most of the Manhattan eastern shore of the Hudson) had very high levels of contamination.
3) Tidal differences or a slight offset in the timing of sample collection may account for some of the observed differences, especially in north/south extent of contamination.
4) The public need to be aware of 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.
1) It matters how/where one samples. On the 21st, mid-channel samples alone would miss most of the contamination (since overflow points were mostly in the Manhattan near shore environment). Near shore sampling is important to proper notification and protection of public health because people are more likely to be coming into contact with the water near shore. We saw people in the water on the west side of Manhattan on both the 21st and 22nd).
2) Our data shows that while many sites far removed from the point sources (pipes used for bypass) did not show a large signal, sites that are in close proximity to the discharging pipes (most of the Manhattan eastern shore of the Hudson) had very high levels of contamination.
3) Tidal differences or a slight offset in the timing of sample collection may account for some of the observed differences, especially in north/south extent of contamination.
4) The public need to be aware of 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.
Phillip Musegaas, Esq.
Hudson River Program Director
Riverkeeper, Inc.
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