A strange material glazed the surface of a northeast Calgary road on Tuesday, leaving crews baffled at what it might be.
Firefighters, police and Calgary roads were called to the scene.
Police closed westbound lanes until the mess was cleaned up.
“The fire crew initially thought it was some sort of human or animal waste,” said Carol Henke, a CFD public information officer.
The fire department said a construction company came back to the scene and took responsibility, saying the spill was pond scum.