"On April 20, 2010, an exploratory oil well in the Gulf of Mexico exploded, killing 11 people and causing the worst oil spill in American history. The oil well was on a tract leased by BP, having obtained a lease and the relevant permits from the federal government. Under relevant federal law, federal actions that may have adverse environmental effects are required to be reviewed for potential environmental harm under the National Environmental Policy Act (NEPA). This report will review those environmental procedures. While there are additional environmental obligations imposed on Outer Continental Shelf (OCS) drilling by other acts, this report will not review those requirements. Multiple environmental reviews were conducted by the Minerals Management Service (MMS) at each stage of OCS development. (MMS was reorganized in May 2010, and the relevant office for the environmental reviews is the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE). This report will refer to MMS for actions before the reorganization and BOEMRE going forward.) For the particular well in question, MMS addressed the environmental impacts on four occasions, including two full environmental impact statements, an environmental assessment, and a categorical exclusion. The fact that MMS categorically excluded the exploration plan from a NEPA analysis is controversial, since that is the first step in which drilling would be conducted. It appears MMS followed its internal procedure for NEPA reviews in the western and central areas of the Gulf of Mexico by employing a categorical exclusion for an exploration plan. However, that procedure has never been reviewed by a court to see if it is consistent with the law or whether an exception to the categorical exclusion may apply in this case. Had this project occurred in a different geographical area, including the eastern area of the Gulf of Mexico, it likely would have undergone a higher level of environmental scrutiny. Following a White House report suggesting that BOEMRE review its NEPA exclusions, BOEMRE announced it would not apply the categorical exclusion used in the Gulf until its review was complete."
CRS Report for Congress, R41265