Oil leaked into the Hudson River on Sunday after transformer failure at a nuclear power station.
The oil leak came a day after the Indian Point nuclear plan north of New York City suffered transformer failure which triggered a fire, forcing the facility to shut down.
Governor Andrew Cuomo visited the plant for a briefing on Sunday, raising his concerns over environmental damage.
The governor, who in the past has called for the plant located 80 kilometers (50 miles) north of New York City to be shut down due to its proximity to the densely populated city, also visited the scene of incident on Saturday.
Cuomo attributed the leak to a transformer on the non-nuclear side of the Indian Point 3 plant.
The transformer released oil into a holding tank, which then overflowed, leaking the oil onto the ground and into the river, Cuomo told reporters on Sunday after he was briefed by emergency and plant officials.
He said emergency crews were dispatched to the area working to contain and clean up the spill.
"If you are on site, you see an oil sheen all over the area where the transformer went on fire, and it was a significant area that was covered by oil, foam and water," Cuomo said.
The transformer explosion and fire at the nuclear power reactor was quickly put out. The fire triggered the closure of the plant's Unit 3 reactor, while the Unit 2 reactor continues to operate.
Entergy Corp, which runs the facility and is one of the largest U.S. nuclear power operators, said the plant was stable and there was no danger to the public or to employees.
Cuomo said emergency crews thought the fire was out but it reignited and had to be extinguished again.
The transformers are located around 300-400 feet (90-120 meters) away from the reactor.
The plant, which dates back to the 1960s, has around 1,000 employees.
The plant produces about 25 percent of New York City and Westchester County’s electricity, according to the operator’s website