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How Is the Water? A story of sewage contamination on the Hudson


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There have been tremendous improvements in Hudson River water quality since the passage of the Clean Water Act in 1972. The public is swimming again. The river is a de facto 155-mile long beach in the summer.

Andy Juhl sampling

In order to better understand, and continue to improve, water quality in the Hudson River, Riverkeeper started its Water Quality Testing Program in 2006. Since that time we have collected over 2,000 samples from 75 set locations throughout the 155-mile long estuary. Although we have found evidence of sewage contamination at every one of our 75 testing locations, the levels of contamination vary enormously over time and by location.

At locations within a quarter mile of each other, we sometimes find very different levels of sewage contamination¬–¬on the same day. In most of the river, we’ve found sites that are frequently Acceptable as well as sites that fluctuate between Acceptable and Unacceptable. Poor water quality at one site does not necessarily mean there will be poor water quality at nearby sites. The Hudson’s sewage contamination is typically a local problem. Once sewage sources are identified, they can often be remedied with local solutions.

Overall water quality in the Hudson failed the U.S. EPA guideline for safe swimming 21% of the times we sampled – the equivalent of 1½ days a week on average. By comparison, water quality samples collected at beaches nationwide failed the EPA guideline for safe swimming 7% of the times sampled over the same period, 2006 – 2010.

During and after rainfall the frequency of Unacceptable Entero counts increases in all the regions and at all the types of sites we sample, but not at every individual location. Overall the percent of samples that were Unacceptable increased from 9% in dry weather to 32% in wet weather–a threefold increase.

Sewage floatables

In some communities, like New York City, as little as 1/4 inch of rain can trigger a sewage overflow. Each year New York City alone dumps 27 billion gallons of combined sewage and storm water into the Hudson. Albany dumps another 1.2 billion gallons. And in between many communities add their additional share. This shows that the recent 200+ million gallon sewage spill in New York City is only a minor contributor to the widespread contamination that occurs regularly throughout the Hudson Valley after rain.

While sewage contamination increases after rainfall at many locations, some locations are contaminated even in dry weather. Our study found sewage contamination is higher near the shoreline and at tributaries where water quality samples were Unacceptable 24% and 34% of the time–far more frequent than rainy weather.

In many near-shore locations contamination is local and community specific. That’s good news for area residents because local contamination problems lend themselves to local solutions.

Riverkeeper Recommendations
In light of these findings Riverkeeper is calling for specific actions on the state, county and local level to begin the elimination of sewage contamination in the Hudson River Estuary and inform the public where and when it does occur.

1) NY State, sewer districts and/or Hudson River counties need to conduct weekly water quality testing at all user areas and develop predictive modeling to forecast water quality and protect public health.

2) New York State must adopt a “single sample” standard for evaluating water quality in order to better reflect the spikes in contamination found in the estuary.

3) New York State must pass a Sewage Right to Know Law that requires timely public notification of sewage contamination in our waterways, both accidental and chronic.

4) Local and state governments must locate contamination sources and prevent sewage from entering the river and its tributaries by investing in wastewater infrastructure.

5) Citizens and communities need to identify and solve their local contamination problems by supporting infrastructure upgrades, green infrastructure projects, improved septic field regulations and maintenance, and water conservation.

Best and Worst Sites
Through 2006-2010, there were only 7 of 75 sites where we never collected an Unacceptable sample: Dyckman Street, Manhattan; Yonkers Wastewater Treatment Plant Outfall, Yonkers; Irvington Beach, Irvington; Croton Point Beach, Croton-on-Hudson; Emeline Beach, Haverstraw; Fort Montgomery, Highlands; Poughkeepsie Drinking Water Intake, Poughkeepsie.

Unfortunately there were 10 other sites that had unacceptable counts 50%, or more, of the times we sampled: Gowanus Canal, Brooklyn – 50%; Newtown Creek, Metropolitan Ave. Bridge, Brooklyn – 53%; Sparkill Creek, Sparkill – 86%; Sewage Treatment Plant Outfalls at Piermont – 50%; Piermont Pier, Piermont – 50%; Tarrytown Marina, Tarrytown – 56%; Newburgh Launch Ramp, Newburgh – 50%; Kingston Wastewater Sewage Treatment Plant Outfall, Kingston – 50%; Island Creek/Normans Kill, Glenmont – 65%; Dunn Memorial Bridge, Albany – 50%.

Each group contains sites from different regions of the Hudson. Some of the cleanest sites we found are surprisingly near some of the most contaminated sites, such as the Tarrytown Marina and Irvington Beach.

We Can’t Manage What We Don’t Measure
There is little testing, or modeling and prediction, for sewage contamination in the Hudson River Estuary. Of the ten counties on the estuary, only four test for sewage contamination at their shorelines, and that testing is limited in scope and frequency. None of these report their findings to the public.

Greg O'Mullan and John Lipscomb sampling

The NYC Department of Environmental Protection (DEP) does test water quality in New York Harbor and publishes findings a year or two later. DEP data is averaged seasonally which means that episodes of extreme contamination caused by rain events are not reported to the public.

Despite this lack of critical data, the Department of Environmental Conservation (DEC) has classified Hudson River waters from north of the Bronx Borough line all the way to the northern end of Columbia County as acceptable for swimming. Without water quality data, pollution sources and impacts cannot be identified. We can’t manage what we don’t measure.

New Yorkers are getting into the Hudson River more and more each year and the question Riverkeeper most often hears from the public is “How’s the water?” In 2006 we launched the Water Quality Testing Program to provide the public with Hudson River water quality data. We believe than an informed, empowered and invested pubic will lead to improvements in water quality.

To distribute our water quality data to the public we have created an online database at that is updated within days of our monthly sampling patrols. We also publish a monthly Water Quality Report based on each sampling patrol that is available as an e-letter.

What You Can Do
The gains in water quality that have been achieved since 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 as are incidents of waterborne illnesses contracted in recreational waters.

You can support our efforts to improve water quality in the Hudson, and in other waterways across New York State by signing Riverkeeper’s petition in support of a New York State Sewage Right to Know Law. A public notification law is a critical tool for improving water quality in the Hudson Valley and across New York.

Read more about sewage contamination in the Hudson River in our How Is the Water? report.

View our online water quality database.

Stay informed of all our clean water work by signing up to receive the Riverkeeper e-letter.

How Is the Water? A story of sewage contamination on the Hudson by Riverkeeper