Photo: Eva Deitch
Water quality monitoring
Riverkeeper is the go-to source for information about the quality of the water along the Hudson River and its tributaries
The challenge
Keeping a diligent eye on water quality in the Hudson River estuary and its tributaries to ensure it is swimmable, fishable, and drinkable.
How’s the water?
While the river is much cleaner than it has been in recent history, it still faces threats from sewage outflows, industrial and agricultural pollution, and climate change.
Our water quality monitoring program — a collaborative effort involving volunteer community scientists, watershed associations, environmental organizations, and academic partners — informs river users, advocates, municipalities, and regulators by identifying and quantifying emerging hazards and ensuring the Hudson becomes an increasingly safe and thriving habitat for both wildlife and the communities that depend on it.
- Focus areas
- Drinking waterWater qualityHabitat and wildlife
What we're doing
Monitoring and analyzing water quality and sharing the results so we can make informed decisions for the river and ourselves.
Since 2006, when Riverkeeper’s Boat Captain John Lipscomb launched the program along with Gregory O’Mullan and Andrew Juhl, both professors at Columbia’s Lamont-Doherty Earth Observatory at the time, we have sampled the waters along the length of the Hudson River from the Battery in New York City to Newcomb in Adirondack National Park, encompassing the Hudson River estuary and eighteen tributaries.
How we test and what we test for
Riverkeeper’s water quality data collection effort has been foundational to a movement that now includes dozens of labs and volunteers spread across hundreds of monitoring sites. Our network of community groups, volunteer community scientists, academic institutions, and nonprofit organizations collects and tests water from the Hudson and its tributaries to identify patterns of contamination, inform decision-making about public recreation, and advocate for water quality improvements.
From May to October each year, our Science team utilizes Riverkeeper’s boat to collect water samples each month at more than 120 sites in the main stem of the Hudson. We test these samples for salinity, dissolved oxygen, temperature, turbidity, pH, chlorophyll, dissolved organic matter, nitrate, and fecal indicator bacteria Enteroccoci.
With our network of volunteer community scientists, we collect hundreds more samples in the tributaries and measure similar parameters at our Kingston, New York water quality laboratory in the Hudson River Maritime Museum. Data collection helps us understand the health of the Hudson, its safety as a source of drinking water, as well as the impacts of climate change on the system and how environmental justice communities in the watershed are impacted by pollution.
We also work regularly with colleges, universities, municipalities, and regulators to collect additional water quality data to understand the sources and occurrence of contaminants of emerging concern, conduct microbial source tracking to better understand where fecal indicator bacteria or nutrient pollution is coming from, and collect data that can be used for regulatory purposes. Over the years, we have formed partnerships with Bard College, SUNY Cobbleskill, Union College, CUNY Queens, Media Sanctuary, and Rensselaer Polytechnic Institute.
Our monitoring program is a reminder that the health of the river is connected to our own health, and in caring for the river we care for all of those who depend on it.
Water Quality Portal
Use this interactive map to explore water quality throughout the Hudson River watershed with data that Riverkeeper and our partners collect. Dive into when and where it is safe to swim and boat, how clean your drinking water is, and the health of the region's fish.
Is it safe to swim in the Hudson?
You might be surprised to learn that fecal indicator bacteria levels in the Hudson do not exceed unsafe levels in most of the Hudson most of the time. However, factors such as boating traffic, currents, tides, and weather events, especially precipitation events that overwhelm infrastructure and result in untreated sewage releases or in large amounts of polluted urban and agricultural runoff, can make open water swimming unsafe. In general, we recommend that beachgoers, swimmers, boaters, and kayakers avoid substantial contact with the Hudson River and New York City waterways after rain.
Convening the Hudson River Water Quality Monitoring Collaborative
Members of the Hudson River Water Quality Monitoring Collaborative share insights at the 2025 symposium.
As part of an effort to increase coordination and cooperation around water quality monitoring throughout the Hudson River watershed, Riverkeeper created the Hudson River Water Quality Monitoring Collaborative. The Collaborative is composed of over 100 stakeholders including academics, regulators, municipalities, watershed groups, and environmental justice groups. It is designed to facilitate sharing of knowledge, expertise, and resources in order to identify and address the most pressing issues facing the watershed. Members of the Collaborative discuss opportunities for novel monitoring strategies and provide feedback that we use to improve Riverkeeper’s monitoring program, making sure it is responsive to current and future threats. A central goal of the Collaborative is to help people and organizations understand and use their own monitoring data to improve their communities.
The Collaborative holds yearly meetings where stakeholders share information and develop strategies to turn their data into action by learning from each other and from Riverkeeper’s advocacy successes that have resulted in improved water quality throughout the Hudson River watershed.
Training the next generation
In 2021, Riverkeeper and Media Sanctuary launched the Water Justice Lab, a project in North Troy that established a water quality sampling lab that trains young students from this underserved community in both laboratory science and media skills in order to shed light on environmental justice issues in the Hudson River watershed. Water Justice Fellows participate in an eight-week long field trip-based course called Source to Estuary, where they learn about their local water systems and create media (radio, photography, video) about what they learn. Partnering with the Kingston YMCA Farm Project, students also learn about the connections between water, agriculture, and environmental sustainability.
Riverkeeper provides equipment, resources, education, training, mentorship, and field experience for the Water Justice Fellows to analyze water quality samples that they collect in their community.
In the Hudson River Watershed, we don’t have equitable access to water that is safe to drink, fish that are abundant and safe to eat, or healthy rivers and streams where we can experience the simple human joy of being in and near water. Through both community science and community media, these students will help shine a light on these issues, so we can all work to remedy them.
Dan Shapley
Senior Director of Advocacy, Policy and Planning
How to get involved
Speak up or participate in an upcoming event related to this campaign.
Updates
Update
November 21, 2025
Standing strong against rollbacks to clean water protections
Update
November 7, 2025
What’s next for Renewable Rikers
Update
November 7, 2025
Hundreds of samples, thousands of measurements, one water quality monitoring season
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