Original: According to the Flow Rate Technical Group , the leak amounted to about 4.9 million barrels ( 205.8 million gallons ) of oil exceeding the 1989 Exxon Valdez oil spill as the largest ever to originate in U.S.-controlled waters and the 1979 Ixtoc I oil spill as the largest spill in the Gulf of Mexico .
Simplified: The Deepwater Horizon oil spill ( also called the BP oil spill , the Gulf of Mexico oil spill , the BP oil disaster or the Macondo blowout ) is an oil spill in the Gulf of Mexico . It is the largest marine oil spill in history .