Westchester has a dirty secret
County must address chronic sewage pollution into the Hudson River
August 5, 2026
Tracy Brown
President and Hudson Riverkeeper
Key takeaways
- The Yonkers Wastewater Treatment Plant, which serves 500,000 people, discharges between 800 million and 1.8 billion gallons of sewage into the Hudson River each year.
- After 40 million gallons of sewage spilled into the Hudson on July 3, the county conducted only routine weekly testing, resulting in 10 days of lost access to the Hudson.
- Fixing the Yonkers wastewater system is essential to protecting public health, local businesses, and the Hudson River's recovery.
Westchester has a dirty secret: It is not treating all of the sewage generated by its residents.
To understand why, you have to start in Yonkers.
The county is divided into 13 different sewer districts. Of these, Yonkers is by far the largest, with the Yonkers Wastewater Treatment Plant treating sewage from most of the towns along the Hudson River and three Westchester cities, including portions of White Plains, Mount Vernon, and New Rochelle. Serving half a million residents who mostly live outside of Yonkers*, the Yonkers plant is the second largest sewage treatment plant on the Hudson River, behind only the North River plant in Manhattan.
Parts of the Yonkers sewer system use what’s called a combined sewer system, where stormwater runoff flows into the same pipes as sewage. When it rains, that extra water can overwhelm the system, forcing the treatment plant to discharge raw sewage into nearby waterways. In Yonkers, this means the county dumps between 128 million and 1 billion+ gallons of partially treated sewage into the Hudson each year. Fifty years after the passage of the Clean Water Act, this is unacceptable.
Thanks to the work and commitment of so many people in the Hudson Valley, including groups like Riverkeeper, the Hudson River is on a path to recovery. That revival has led communities and businesses to stake their livelihood on a healthy Hudson River. Westchester County encourages the cultural, economic, and recreational connection to the river — but without taking our sewage treatment and disposal seriously, they are setting these communities up for failure.
The county’s lack of preparation came into focus this summer. During a heat wave, on July 3, 2026, the Yonkers Wastewater Treatment Plant went offline when Con Edison — overwhelmed by demand from overheating communities — reduced power to the plant by 8% and the plant's backup generators failed. As a result, approximately 40 million gallons of sewage was dumped into the river in Yonkers.
The county closed public access to the Hudson River in a necessary move to keep the public from being exposed to the disease-causing pathogens in untreated sewage. However, officials did not follow up with daily testing of the water to figure out when the water quality had improved. While residents sweated, paddle boarding and kayaking was canceled, and our river access was barricaded, the county went on with business as usual, not testing the river again outside their routine once-a-week Monday sampling. When those samples came back clean on July 14, they did not make an announcement saying that the closure of the river had been lifted until July 16 - nearly two weeks after the initial warning.
Video loading...This left residents and local businesses in a state of confusion. Riverkeeper reached out to county leadership and got no response. Our own testing, along with testing from our partners at the Center for the Urban River at Beczak and the Hudson Valley Stream Conservancy, showed that the river was indeed recovered and safe for recreational use within five days after the spill, on July 8, and possibly sooner.
The Yonkers discharge was a failure of infrastructure, planning, and communications. Not all of the community’s wastewater is treated because the plant still relies on an outdated combined sewer system and insufficient backup power scenario planning took the entire plant offline for 17 hours over July 4th weekend. The county's response was limited, leaving the public in the dark with some river access points open and others shuttered indefinitely.
The County Department of Health tests water quality only at certified beaches, leaving much of the Hudson unmonitored. Even at those beaches, testing typically occurs just once a week, meaning elevated bacteria levels can go undetected for days before the public is warned or beaches are closed.
With so little monitoring of the Hudson's water quality, the public has to rely on our wastewater systems to do their job. Sewage should stay in the pipes until it reaches the treatment plant, and once it gets there, it should all be fully treated — not diverted around the treatment process and discharged into the Hudson River.
For years, Riverkeeper has been lobbying New York State to do a full assessment of the discharge permit at the Yonkers plant and its sewage pollution issues, and this year they have agreed. Once the Yonkers plant's needs are thoroughly documented and the cost of bringing the facility into good working order is established, Westchester, Albany, and Washington should have every reason to provide the funding required to fix the system.
Your voice can help shape the future of wastewater treatment in our communities and pollution in our waterways. We encourage clean water supporters who care about the health of the Hudson and having access to the river to communicate concerns to your local and county elected officials. Join Riverkeeper’s email list to hear about how and when you can take action.
Sewage pollution not only threatens public health, it diminishes our quality of life and hurts the local businesses, communities, and wildlife that depend on a clean Hudson River. Residents deserve timely water quality testing after sewage spills, clear public communication about closures and reopenings, and a wastewater system that protects the river instead of polluting it.
Riverkeeper will continue to push for the investments, transparency, and accountability needed to ensure the system works for the river and for us all.
For a deeper dive, watch the video and read the public comments I provided to the Westchester County Board of Legislators on this issue alongside our partners in the Westchester Coalition for Clean Water.
*The communities whose wastewater is treated at the Yonkers Wastewater Treatment Plant are: City of Yonkers, Northern Bronx, Hastings-on-Hudson, Greenburgh, Mount Pleasant, Tarrytown, Dobbs Ferry, Pleasantville, Sleepy Hollow, Irvington, Ardsley, Valhalla, Mount Vernon, Pelham, White Plains, Scarsdale, Eastchester, Tuckahoe, Bronxville, Mount Kisco, Chappaqua, and New Castle.
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