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
Deepwater Horizon oil spill more than wide and deep. In a major study on the plume, experts were most concerned about the slow pace at which the oil was breaking down in the cold, water at depths of . In late 2012, a study from Georgia Tech and Universidad Autonoma de Aguascalientes in Environmental Pollution journal reported that Corexit used during the BP oil spill had increased the toxicity of the oil by 52 times. The scientists concluded that "Mixing oil with dispersant increased toxicity to ecosystems" and made the gulf oil spill worse." The three basic approaches for removing the oil from the