WILLOUGHBY, Ohio (WJW) — An oily sheen was spotted on the Chagrin River around noon Wednesday, the Fire Chief City of Willoughby Fire Department said.

At this time, cleanup crews have not yet identified the substance, but Fire Chief Todd Ungar told FOX 8 everything tested so far “has come up negative as far as flammability or any toxicity.”

The U.S. Coast Guard, the Lake County Hazardous Materials team and the EPA are currently on scene at Chagrin River Park, working to make sure the spill is entirely removed. Booms have been placed in the water to help corral the substance to one area so it can easily be vacuumed out.

Ungar told people to stay out of the water and to allow the cleanup crews to work. However, he did not believe there was any immediate danger.

“I really don’t know enough about what’s in the water yet, I don’t think there’s too much of a hazard at this point,” he said.