State inspectors discovered the bad gas in samples taken at the Sunoco on West Pike Street in Canonsburg on Dec. 22, the department says.
Drivers had contacted the department with their concerns after their vehicles broke down and mechanics informed them that water in the gas might be the cause -- something the department has now confirmed.
The pumps at the station were closed until the issue is corrected, and tests return normal, officials said.
Click here to read more from WPXI.
Click here to follow Daily Voice Gettysburg and receive free news updates.