Hazmat was called after a van crashed into a 55-gallon drum of used motor oil Sunday night. The accident happened in the 200 block of New Laredo highway.
Police said the driver of the van lost control on wet roads, and crashed into the drum. It sent the oil into a nearby drainage ditch.
The fire department was forced to bring out the Hazmat crew and set up booms around the oil to keep it from spreading.
"We want to get it cleaned up before it rains so we're working on contacting somebody to get a vac truck or however public works would like us to handle that," said Lt. Hank Schott of the San Antonio Fire Department.
The fire department also contacted TCEQ to inform them about the minor spill. The driver was treated at the scene, but officials did not provide details about his condition or possible injuries.