BROOKLYN, N.Y. - Some Brooklyn residents were worried Thursday over a green goo that spilled into the Gowanus Canal.

But it turned out to be perfectly safe.

The city's Department of Environmental Protection says the green stuff was just a harmless dye that had been used to test the agency's infrastructure.

"I was like, 'Whoa.' It's kind of alarming at first, trying to figure out what it is. You never expect to see lime green substance coming out of a drain. My initial thought was if it's safe," said one passerby.

The DEP says the dye will eventually dissipate in the water.