By Dan Murphy
On the evening of July 2 into the morning of July 3, Westchester County and all of the region were hit with temperatures of 100 degrees. During the heat wave, Con Edison cut electric power by 8% to NYC and Westchester in an attempt to avoid a blackout.
On July 2–3, 2026, the Westchester County Yonkers Joint Sewage Treatment Plant suffered a major power breakdown that resulted in the discharge of 39 million gallons of chlorinated, partially treated sewage into the Hudson River.
The incident unfolded over the busy Independence Day holiday weekend due to a mix of extreme weather and equipment failure:
The Cause: During a severe regional heatwave, Con Edison initiated emergency power reductions. The massive reduction in voltage placed an intense, unexpected strain on the treatment facility’s equipment. While the plant’s backup generators initially kicked on as designed, the compounding mechanical stress caused the backup system to fail, leading to a complete power outage at the facility.
On July 2, Con Edison stated, “Con Edison is asking customers in certain areas of Yonkers, Pelham, Mount Vernon, Bronxville, Eastchester, New Rochelle and the town of Mamaroneck in Westchester, and in certain areas of the Northeast Bronx and City Island, to conserve energy while crews repair equipment. Con Edison has reduced voltage in the area by 8 percent to protect equipment and maintain service as crews make repairs.
“The Westchester area is roughly bounded by the Bronx on the south, parts of Eastchester and New Rochelle on the north, parts of Yonkers and Tuckahoe on the east, and parts of New Rochelle and Mamaroneck on the west. The affected area also includes some customers in the northeast part of the Bronx and on City Island. The total customer count is 89,000.”
The Spill: The power failure began on the night of Thursday, July 2, and paralyzed the main processing systems. Operators bypassed standard treatments to avoid a catastrophic internal backup, leading to the 39-million-gallon discharge. The plant was not fully operational again until 1:45 p.m. on Friday, July 3.
The Impact & Health Advisories: The Westchester County Department of Health immediately issued an emergency advisory warning residents to avoid all direct, recreational contact with the Hudson River—including swimming, kayaking, paddleboarding, boating, and fishing.
Affected Areas: The water quality advisory stretched from the New York City line north through several Westchester riverfront communities, including Yonkers, Hastings-on-Hudson, Dobbs Ferry, Irvington, Tarrytown, Sleepy Hollow, and Briarcliff Manor. The Philipse Manor Beach Club in Sleepy Hollow was also ordered closed. While the plant quickly returned to full operations on July 3, county health officials kept the recreational river advisories in place well into the following week to allow residual contamination to clear and water quality testing to return to baseline safety levels.
Con Edison maintains that power flow in Yonkers continued for July 2 and 3, and that the 8% voltage reduction would not have completely shut down the plant.
Initially, County Executive Ken Jenkins office stated in a release that the failure was “due to the power reductions by Con Edison from the extreme heat.”
That comment was later corrected to include power issues” as a possible cause.
The New York Times covered the story (https://www.nytimes.com/2026/07/03/nyregion/sewage-spill-hudson-river.htmlnternal
and included, “According to a state report released Friday night, the Yonkers plant lost power because of extreme heat and humidity and could not transfer power over to its generators.” We have not been able to identify or obtain that report.
But neither the NY Times nor the Journal News, which also covered the event, did not identify the actual cause of the massive spill or who is to blame. Residents in Southwest Yonkers who live near the plant DO WANT ANSWERS, and others have called for an investigation.
Some posts on social media include former employees at the plant and those with knowledge of the backup generators, which appear to have failed at a critical point.
One post wrote, “I just retired from there out of fear that someone would get hurt and that I would be held responsible for something beyond my control. New York State should witness actual full load generator testing as they always have instead of simply saying, “Do it yourself and let us know when you’re done.”
Another post wrote, “I was the Superintendent of Maintenance at the plant. A few years back, the plant had a major generator failure that would have been prevented if the Deputy Commissioner had acted on the concerns I raised. Instead, my concerns were ignored, and the plant went down for an extended period.
The DEC investigated the previous incident, and the facts were twisted or misrepresented. As a result of that incident, another engineering study was ordered. An engineering firm was hired to evaluate the emergency generator and determine what equipment could safely be operated on generator power.
I was told that the State, along with the engineering firm, would conduct a full load test of the emergency generator. I welcomed the test because I wanted to see whether the recommended equipment list would actually perform as expected while operating on generator power.
I kept asking when the load test would be scheduled. I was repeatedly told that the State had not provided a date. I continued to ask, but my questions were ignored. To my knowledge, the load test was never conducted.”
The residents of Southwest Yonkers deserve answers, and so do the thousands of Westchester residents who use the Hudson River for recreation every day.
Note: The Water Treatment plant is operated by Westchester County. The City of Yonkers has not oversight or authority over it.
