<P> Numerous investigations explored the causes of the explosion and record - setting spill . Notably, the U.S. government's September 2011 report pointed to defective cement on the well, faulting mostly BP, but also rig operator Transocean and contractor Halliburton . Earlier in 2011, a White House commission likewise blamed BP and its partners for a series of cost - cutting decisions and an inadequate safety system, but also concluded that the spill resulted from "systemic" root causes and "absent significant reform in both industry practices and government policies, might well recur". </P> <P> In November 2012, BP and the United States Department of Justice settled federal criminal charges with BP pleading guilty to 11 counts of manslaughter, two misdemeanors, and a felony count of lying to Congress . BP also agreed to four years of government monitoring of its safety practices and ethics, and the Environmental Protection Agency announced that BP would be temporarily banned from new contracts with the US government . BP and the Department of Justice agreed to a record - setting $4.525 billion in fines and other payments . As of February 2013, criminal and civil settlements and payments to a trust fund had cost the company $42.2 billion . </P> <P> 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 . </P> <P> In July 2015, BP agreed to pay $18.7 billion in fines, the largest corporate settlement in U.S. history . </P>

Who is responsible for deepwater horizon oil spill