Efforts to stem the Deepwater Horizon oil spill Efforts to stem the Deepwater Horizon oil spill Efforts to stem the "Deepwater Horizon" oil spill were ongoing from the time that the "Deepwater Horizon" exploded on 4/20/2010 until the well was sealed by a cap on July 15, 2010. Various species of dolphins and other mammals (61 casualties), birds (2,095 casualties), and the endangered sea turtles (467 casualties) have been killed either directly or indirectly by the oil spill. The "Deepwater Horizon" spill has surpassed in volume the 1989 "Exxon Valdez" oil spill as the largest ever to originate in U.S.-controlled waters; it is comparable to the 1979 Ixtoc
Deepwater Horizon oil spill and payments to a trust fund had cost the company $42.2 billion. In September 2014, a U.S. District Court judge ruled that BP was primarily responsible for the oil spill because of its gross negligence and reckless conduct. In July 2015, BP agreed to pay $18.7 billion in fines, the largest corporate settlement in U.S. history. How the misuse of categorical exclusion for National Environmental Policy Act (NEPA) compliance relates to this spill is described in Regulatory Capture. The "Deepwater Horizon" was a 10-year-old semi-submersible, mobile, floating, dynamically positioned drilling rig that could operate in waters up to deep. Built