How you can use the data
Riverkeeper’s water quality data can help you assess the safety of river and tributary locations for recreation. We measure the amount of fecal indicator bacteria (enterococcus) that are present once per month and share that data on our website. EPA’s threshold for safe recreation is 60 counts/100 mL. If the sample meets this threshold, you will see a green circle on our website at that location. Fecal indicator bacteria indicate the presence of potentially harmful pathogens that can lead to skin and gastrointestinal problems. Therefore, if the enterococcus count at a location is frequently above 60, you may want to take precautions before swimming or wading.
Recent reports
View our most recent reports:
Community science
If you want to help us collect and analyze water samples in your community, there are citizen sampling sites throughout the tributaries of the Hudson where you can collect samples that provide us with valuable data about water quality in the watershed.
Where we test
In collaboration with community scientists and dozens of other organizations, Riverkeeper displays the results of water quality testing from 337 locations throughout the Hudson River watershed.
What we test
Riverkeeper’s Hudson River estuary water quality monitoring program has been measuring salinity, dissolved oxygen, pH, water temperature, turbidity, chlorophyll, and Enterococcus (Entero), a fecal indicator bacteria since 2006. Starting in 2024, we also added nitrate, phosphorus, organic matter and total blue green algae to our list. Most tributary and waterfront projects have only been monitored for Enterococcus in the past, but starting in 2025, we will also measure chloride, dissolved oxygen, pH, water temperature, turbidity, nitrate and phosphorus. The unprecedented scope of Riverkeeper’s community science data collection network has allowed for the formation of partnerships to study the occurrence of other contaminants in the watershed as well, such as pharmaceuticals and personal care products, disinfection byproducts and use techniques to better understand the sources of pollution.
Our monitoring boat and Kingston laboratory are equipped with the IDEXX Enterolert system to test for Enterococcus and handheld sensors and test kits are used to measure other parameters.
As the water flows past the sensors, our equipment records the concentrations of the parameters listed above and those data are interfaced with a GPS unit so that the time and location of each measurement (in latitude and longitude) are also recorded. Using Enterococcus data we assess the safety of each sampling location for recreation based on EPA’s Federal Recreational Water Quality Criteria for safe primary contact (swimming and immersion).
Our routine data collection does not include polychlorinated biphenyls (PCBs), radioactivity, mercury, heavy metals, or other industrial contaminants. However, these and other pollutants may be measured in certain locations via partnerships with the scientific community.
Request data
To request data, please contact us via this request form.
Related campaigns
Water quality monitoring
Riverkeeper is the go-to source for information about the quality of the water along the Hudson River and its tributaries
Protecting Hudson River watershed drinking water at the source
Riverkeeper ensures that drinking water sources stay clean and safe through vigilant advocacy and conservation efforts
Sewer and stormwater pollution
Working to keep sewage and street pollution out of our waterways