Jeff Mays, Kareem Johnson and Tom Liddy, DNAinfo Staff
MANHATTAN — Thousands of people were evacuated from a packed Harlem park Wednesday afternoon after an explosion triggered a roaring fire at a sewage treatment plant that spewed a 30-foot plume of fire into the air, officials said.
The ferocious four-alarm blaze, which also snarled traffic on the West Side Highway, broke out in the engine room of the city's North River Wastewater Treatment plant, at 725 W. 135th St., at 11:46 a.m., an FDNY spokesman said.
"There was heavy fire, heavy smoke," said FDNY Deputy Assistant Chief Joseph Woznica. The cause of the fire, which raged for hours, was not immediately clear, but Woznica said that pressurized fuel helped spark a "30-foot plume of fire."
Riverbank State Park, which sits on top of the plant, was evacuated as a precaution, according to the New York State Parks Department. And the West Side Highway was also temporarily shut between 125th Street and 153rd Street, NY1 said.
Rachel Gordon, the regional director for the Parks Department, said that several thousand people were inside Riverbank Park at the time, including the elderly and kids going to camp.
"There was overwhelming black smoke," she said. "It was quite intense."
But workers sprang into action, combing through the park to usher everyone to safety.
Plant employees said that they heard what sounded like an explosion, followed by an alarm telling them to evacuate.
"There was a lot of smoke," said one, who did not want to give his name. "We smelled it. It was really thick smoke. We couldn't see through it."
Several workers told DNAinfo that they had been having problems with one of the engines on Tuesday.
Parkgoer Jonathan Williams, 36, a contractor, was swimming in the park's pool at the time when he smelled smoke.
"I was in the pool and then this black smoke started coming out," said the contractor, who had to leave his clothes behind in the rush to evacuate. "I stepped out because I take [asthma] medicine and didn't want to get sick.
"[The smoke] was high up in the air and it smelled terrible."
And Patricia Vitucci, who works in PR, said that she had just stepped out of the park's cultural center, near West 145th Street, when she saw smoke.
"We heard the fire alarm in the park and then we heard it on the radio," she said. "When I came out, I saw black smoke billowing."
"It was in the air and spreading. It smelled like something chemical."
VItucci said that there's been concern in the community about Riverbank Park's proximity to the plant.
"It's a concern with the plant here because sometimes the smoke stacks smell and you don't know what's going on," she said.
Two firefighters were treated for heat exhaustion, the FDNY said.
DEP Commissioner Cas Holloway said that the plant was taken offline until repairs could be made. In the meantime, sewage would collect there until it could be processed.
"The plant has [5 to 7] hours storage capacity," he said. "We're not bypassing the intake to the plant."
But in the event that the capacity is reached, raw sewage could flow directly into the Hudson.
"At this time we don't expect any impact ot businesses or homes," he said.
The North River plant was first proposed in 1914, but the Harlem location was not chosen until 1962, according to the city Department of Environmental Protection's website.
The 26-acre facility started preliminary treatment of waste water in 1986, stopping the daily flow of raw sewage into the Hudson for the first time, according to DEP.
The $100 million Riverbank Park, which has an Olympic-size pool, a skating rink, cultural center, 2,500-seat athletic complex and a restaurant, was a key part Harlem's agreement with the city in accepting the controversial plant. Several other neighborhoods fought against locating it in their areas.
In the wake of the 2003 blackout, investigators reportedly found that a lack of working generators at the plant posed the risk for a "catastrophic explosion." The generators powered a flame that burned methane gas produced there.
At the time, the DEP denied that there was a danger.
Peggy Shepard, the executive director of the Upper Manhattan advocacy group WE ACT for Environmental Justice, sued the city in 1992 to try to stop the plant.
"We've been concerned all along about maintenance at the North River property because its operation depends on strong maintenance and a well educated staff," she said.