It happened at the intersection of Broadway Road and 4th Street just outside of Morton.
Police say a large farming implement fell off the side of a bridge and spilled a herbicide containing atrazene into a creek. Diesel fuel also spilled. Now crews are working to keep the problem from getting any worse.
"We looked down about two and a half miles," said Pekin Fire Chief Kurt Nelson. "We didn't find any contamination in that area but it does basically mix with water. We diked down in that area and also put up some booms to collect any of the diesel fuel that also spilled out of the tractor."
The farm implement's driver was taken to a local hospital. There's no word on the extent of the driver's injuries.