Raw sewage that had been spilling into the Hudson River was stopped on Friday night after pumps at a wastewater treatment plant began working again.
Untreated discharges of wastewater stopped at about 9:30 p.m. Eastern time, said Farrell Sklerov, a spokesman for the city's Department of Environmental Protection. Two engines used to pump wastewater had been brought back online earlier in the day.
About 200 million gallons of sewage had gone into the water, affecting area beaches and fishing. But authorities didn't expect any long-term effects.
Department of Environmental Protection Commissioner Caswell Holloway said the pumps were handling all the incoming flow, and sewage that had been stored in the system was being reduced. But there was still another critical part of the treatment process that needed to be fixed before the system would be working normally. It was unclear how long it would take to get the entire system up and running.
Deputy Mayor Stephen Goldsmith praised the "heroic work" done around the clock to get the Manhattan plant back in service.
The North River Wastewater Treatment Plant was taken offline Wednesday following a fire in the engine room. Untreated wastewater began flowing into the river at 5:15 p.m. Wednesday. The fire is being investigated.
"This is one burned-out place," Goldsmith said. "There are a lot of precarious moments yet."
Pollution advisories were in effect at three beaches on Staten Island and one in Brooklyn. Swimmers and kayakers in New York and New Jersey were urged to stay out of the river, and fishermen were urged to toss their catches back into the water.
Riverbank State Park in Harlem has reopened, but two pools there will remain closed until Saturday. The 28-acre recreational complex is on top of the plant.
Dr. Thomas Farley, the head of the city Department of Health and Mental Hygiene, said scientists were sampling water at the area beaches daily to determine whether levels were safe. He said the tests take about 24 hours, and beaches could possibly close Saturday because of unsafe levels, but it was unlikely.
Scientists from the New Jersey Department of Environmental Protection were monitoring conditions by boat. They were conducting scientific modeling of the tides and currents to gauge whether the spill could have an impact on New Jersey.
The modeling showed that even if repairs were not made until Tuesday, there would not be an impact on Jersey shore points and shellfish beds, state DEP spokesman Larry Ragonese said.
To the north of the city, Westchester County's health department notified its residents to avoid direct contact with the Hudson River through the weekend.
The plant has been in operation since 1976 and treats on average 120 million gallons of wastewater a day.