Volume and extent of the Deepwater Horizon oil spill Volume and extent of the Deepwater Horizon oil spill The "Deepwater Horizon" oil spill was discovered on the afternoon of 22 April 2010 when a large oil slick began to spread at the former rig site. According to the Flow Rate Technical Group, the leak amounted to about 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. BP has challenged this calculation saying that it is overestimated as it includes over of oil which was
Ashland oil spill Ashland oil spill The Ashland oil spill was an oil spill that occurred on January 2, 1988 into the Monongahela River near the town of Jefferson Hills, Pennsylvania, approximately 20 miles upstream from the city of Pittsburgh. Ashland Oil Company Inc. (currently known as Ashland Inc.) owned a facility near the Monongahela River in Jefferson, PA (now Jefferson Hills). On January 2, 1988, a four-million gallon tank was used for the first time after being dismantled (from an Ohio location) and rebuilt in Pennsylvania. It was this tank, holding approximately 3.5 million gallons of diesel oil, that failed and collapsed,