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
Environmental impact of the Deepwater Horizon oil spill that the damage from the spill would rapidly resolve, three years into the recovery dolphins continue to die, fish are showing strange lesions, corals in the gulf have died and oil still remains in some marsh areas. Due to both its size and the way it was handled, there is little previous research to predict long-term effects. At the 2013 "Gulf of Mexico Oil Spill and Ecosystem Science Conference", oceanographer David Hollander presented data that showed as much as one-third of the oil released during the spill may still be in the gulf. Researchers described a phenomenon called "dirty blizzard":