Firefighters from the Morton-Rutledge Fire Company were called to 62 South Morton Avenue in Morton at 10:45 a.m. for a report of a chemical in the creek.
Once on the scene, they reported an unusual odor and a sheen on the surface of the water.
The firefighters put containment booms around the chemical and contacted the Swarthmore Fire Department, which found evidence of the material farther upstream.
Further investigation revealed the chemical may have come from a PVC pipe protruding from a building in Springfield.
The Pennsylvania Department of Environmental Protection has been called in to the investigation.