Hudson River Estuary
Find the latest data from the Hudson River Estuary, as well as data from 2006, when we began sampling the Hudson. Our routine monitoring of 74 locations between New York Harbor and Waterford began in 2008. All data is gathered in partnership with CUNY Queens College and Columbia University’s Lamont-Doherty Earth Observatory.
Where is it safe to swim in the Hudson River?
See Riverkeeper’s annual How’s the Water? report.
Tributaries and Waterfronts
In partnership with community scientists and dozens of organizations, we test many tributaries of the Hudson, and water access sites, for fecal indicator bacteria and other water quality indicators. These samples are collected from the water’s edge by Riverkeeper-trained community scientists, and processed in our onboard lab, our lab in Kingston, or one of our partner labs. We encourage communities to use this data to restore and protect their local waterways.
Water Quality Reports
Find past How’s the Water? reports, as well as reports detailing analysis of data gathered in each tributary watershed we sample, including the Mohawk River, Upper Hudson, Catskill Creek, Esopus Creek, Rondout Creek, Wallkill River, Roeliff Jansen Kill, Saw Kill, Pocantico River, Saw Mill River and Sparkill Creek.
Scientific Publications
Our partners at Columbia University’s Lamont-Doherty Earth Observatory and CUNY Queens College, and scientists at other institutions, have published many studies in the scientific literature, based on our water quality monitoring projects.
Resources for Understanding Improving Water Quality
Meet our water quality program science partners and supporters >
Riverkeeper’s Hudson River Estuary water quality study measures salinity, oxygen, temperature, suspended sediment, chlorophyll, and Enterococcus (Entero), a fecal indicator bacteria. Most tributary and waterfront projects monitor only for Entero. The unprecedented scope of Riverkeeper’s community science data collection network has allowed for several additional studies, ranging from nutrients to pharmaceuticals.
The routine data collection does not include analysis of water or soil contamination that may result from polychlorinated biphenyls (PCBs), radioactivity, mercury, heavy metals, or other industrial contaminants. Learn More
In order to characterize the level of sewage-related microbial contamination in the Hudson and its tributaries, the study applies the United States Environmental Protection Agency (EPA) method 1600 to quantify the abundance of Enterococcus bacteria, a reliable indicator of fecal-contamination. Enterococcus counts are useful as a water quality indicator due to their abundance in sewage, correlation with many human pathogens and low abundance in sewage-free environments.
From Riverkeeper’s patrol boat on the Hudson, discrete samples are taken at 74 sampling sites. Each site falls into one of four categories: 1. Midchannel, deep water; 2. Sewage treatment plant outfall; 3. Tributary; 4. User location (boat launch or swimming beach). Together these sites reflect the variability of this complex environment and are designed to detect both background and extreme sewage loading conditions.
An onboard sensor system is used to measures salinity, oxygen, temperature, suspended sediment, and chlorophyll.
For our tributary and waterfront sampling, we train citizens to collect water samples from the water’s edge. The samples are processed in one of several labs: our onboard lab, our lab in Kingston at the Hudson River Maritime Museum, or at partner labs at SUNY Cobleskill, SUNY Poly, Bard College, Sarah Lawrence College’s Center for the Urban River at Beczak, and Ossining High School; and to support New York City waterfront sampling, The River Project, CUNY Queens, LaGuardia Community College, Brooklyn College, John Jay College and Rocking the Boat.
These Quality Assurance Project Plans document the planning, implementation, and assessment procedures, as well as specific quality assurance and quality control activities, for Riverkeeper’s Hudson River and citizen science projects. These plans integrate all the technical and quality aspects of the projects in order to provide “blueprints” for obtaining reliable data.
Lower Hudson Community Science Water Quality Testing Program (2017)
Please do not post any data from the Riverkeeper website directly on any other website. However, linking to the Riverkeeper website, or to individual pages on the Riverkeeper website, is encouraged.
If the Riverkeeper website data are used as background or ancillary information for any presentation, publication, website, or educational product, we would appreciate proper acknowledgement-
For Hudson River Estuary and Upper Hudson data:
“Data collected by O’Mullan GD, Juhl AR, and Lipscomb J, available at www.riverkeeper.org.”
For East River data:
“Data collected by O’Mullan GD and Lipscomb J, available at www.riverkeeper.org.”
For most tributary data:
“Data collected by Riverkeeper in partnership with residents of the Hudson Valley, available at www.riverkeeper.org.”
For New York City-area water access point data: “Data collected by New York City Water Trail Association and The River Project, in partnership with more than 20 community boathouses, community groups, and waterfront parks.”
For Mohawk River data: “Data collected by Riverkeeper, SUNY Cobleskill and SUNY Poly, available at www.riverkeeper.org.
For Saw Kill and Roe Jan data, “Data collected by Bard Water Lab in partnership with Riverkeeper and residents of the Hudson Valley, available at www.riverkeeper.org.
If you would like to use the Riverkeeper website data as an integral contribution to any publication or educational product, please contact us to discuss potential collaboration and appropriate determination of authorship – [email protected].
Thank you for respecting the efforts of many individuals that have gone into collecting, processing, maintaining, and disseminating these valuable data.
To learn about our findings, please see our How’s the Water reports, tributary watershed reports, or other reports.
Riverkeeper’s Clean Water Action Agenda calls for:
1) Frequent monitoring and public notification
2) Wastewater infrastructure upgrades
3) Stormwater management
4) Local actions to address local sources of sewage contamination
The early gains in water quality that were achieved in the 1970s after the passage of the Clean Water Act are now at risk of being lost because our federal, state and local governments have not continued to maintain and update our wastewater infrastructure. Nationwide sewage contamination in our waterways is on the rise due to increasing failures in our wastewater infrastructure. As precipitation patterns change due to the climate crisis, aging water infrastructure will fail more frequently, resulting in degraded water quality – unless water infrastructure is upgraded sufficiently.
The Water Quality study does not focus on the toxic and radioactive pollutants impacting the river. These pollutants generally have little effect on whether waters are safe for swimming, and instead concern the food chain. Learn More
To learn about “micropollutants” such as pharmaceuticals, personal care products and pesticides, see our page about Pharmaceuticals.
Recent news and inquiries from the public suggest that some people have concerns about swimming safety in the Hudson River during dredging. For most of the river, the NYS Department of Health’s usual advice applies. That advice is that people who wish to swim in a river or lake can take steps to reduce exposure to bacteria and microorganisms. For the immediate area in the upper river where dredging activities are occurring, there are additional safety concerns. This fact sheet highlights NYSDOH advice for those who choose to swim in the Hudson River.
NY State Department of Health Fact Sheet