HARLEM — You can go to the beach, but you can't go in the water.
New Yorkers desperate to escape Friday's sweltering heat are being told not to swim at four beaches in Brooklyn and Staten Island because of raw sewage that's still spewing into the Hudson River after Wednesday's fire at Harlem's North River Wastewater Treatment Plant.
The blaze knocked the plant offline, meaning that up to 130 million gallons of untreated sewage a day have been flowing into the Hudson since Wednesday evening.
After warning New Yorkers Thursday to stay out of the East and Hudson rivers, the Department of Environmental Protection advised beach goers Friday to avoid the surf in South Beach, Midland Beach and Cedar Grove Beach on Staten Island and Brooklyn's Sea Gate Beach.
"Water quality modeling indicates that these beaches have been potentially impacted by the untreated sewer discharges from the North River Wastewater Treatment Plant," the DEP said in a statement.
"Though the beaches are not closed, the New York City Department of Health does not recommend swimming and bathing until this advisory is lifted, especially for people with underlying medical conditions, or young or elderly people who may be more likely to get sick if beach water is swallowed," the DEP said in a statement.
The water remains open so far at city beaches including Coney Island and others.
Mayor Michael Bloomberg said one of the treatment plant's motors shoud resume pumping shortly and that he expects another to be back online later today, during his weekly radio talk show with WOR's John Gambling.
"That's all they need is two," Bloomberg said. "They have five."
The mayor also said the sewage "doesn't have a very big impact."
Phillip Musegaas, Hudson River Program Director for Riverkeeper, a watchdog and advocacy group that monitors the waterway, disagreed. He said more city beaches will likely have to close if the city is unable to stem the tide of untreated sewage today.
"The main concern is public health exposure. If you are in the water and have a cut or scrape you are at risk for infection. If you ingest water that has a higher bacteria count, you are at increased risk of getting sick from gastrointestinal problems," he said.
"It's very serious, especially now that you have large numbers of people looking to utilize the rivers and beaches."
Raw sewage can have up to 200 times the recommended limit of bacteria, said Musegaas. Riverkeeper samples taken from the Hudson last week showed that bacteria levels in the river were well below established limits.
The group criticized the DEP for not doing enough to notify swimmers, kayakers and boaters to stay out of the water. While taking samples on Wednesday and Thursday, the group still found kayakers in the water not far from the plant.
Riverkeeper testers also found people swimming in the water near Dyckman Street yesterday afternoon, Musegaas said.
"They need to do more. If it's a real public health risk, every city agency should be coordinating to get people out of the water, not just saying don't go in," Musegaas said. "The better information we can get out to the public, the better off we are."
Many Riverbank Park goers said they did not know a sewage treatment plant was located underneath the park.
DEP has closed the park built atop of the treatment plant on the Hudson River, west of the Henry Hudson Parkway from 137th Street to 145th Street.
DEP also says they are making efforts to keep people out of the water.
The NYPD Harbor Unit is patrolling near the park to keep boaters at a safe distance. Access to the 79th Street Boat basin is being restricted, as are other boat launch areas along the Hudson River.
The plant, which serves the west side of Manhattan from Greenwich Village to Inwood, treats about 125 million gallons of wastewater every day when the weather is dry. When it rains, it processes about 340 million gallons.
Some of the wastewater is being funnelled to the Wards Island Wastewater Treatment Plant on the East River, but the majority is being pumped directly into the Hudson and East rivers.
The fire broke out in the engine room of the plant Wednesday, an FDNY spokesman said.
Several workers told DNAinfo that they had been having problems with one of the engines on Tuesday.
Musegaas said the river is capable of recovering from the spill.
"It's not like the BP oil spill that will destroy the eco-system," he said. "The river will recover as long as they are able to stop the flow of sewage."