The swim race will go on Saturday in the city's first Ironman U.S. Championship triathalon.
A leaking sewage pipe in Westchester County threatened to cancel the swim portion of Saturday's race.
The pipe is no longer leaking and officials for the Ironman race say the Department of Environmental Protection showed the water is safe for swimming.
The swim course is about 15 miles south of the discharge point.
"They've got an awful lot of people that are worrying about it, are testing the water," said Ironman participant Mike Wien. "If they say we can go in, I'm sure we'll be fine."
"Health officials I've read say that it's not going to affect the overall toxicity of the water," said Ironman participant Trevor Albert.
"This is what happens in an outdoor sport," said Ironman organizer John Koff. "You can have different things affect different aspects. But it is what it is. Our trialthletes know that. They understand that. But believe me, an Ironman athlete is a tough guy. They want to get in the water and swim."
After the 2.4 mile swim, racers hop on their bikes for 112 miles then run a full marathon distance of 26.2 miles.