Court Allows Chemical Safety Board To Investigate Owner Of Deepwater Horizon Rig

A federal appeals court on Sept. 18 affirmed the authority of the Chemical Safety and Hazard Investigation Board (CSB) to investigate the owner of the Deepwater Horizon drilling rig.

Transocean Deepwater Drilling owned and operated the rig that was drilling at BP’s Macondo well in April 2010 when an explosion killed 11 crew members. The rig then leaked oil into the Gulf of Mexico for months, leaving dead wildlife and fouled beaches in its wake.

Transocean challenged CSB’s authority to investigate oil spills in marine waters. In a 2-1 decision, the New Orleans-based U.S. Court of Appeals for the 5th Circuit upheld a lower court’s 2013 ruling that CSB has jurisdiction to probe the accident.

The appeals court noted that as an independent federal agency established by the 1990 Clean Air Act Amendments, CSB has broad power to examine the accidental release of hazardous materials into the air from stationary sources.

Transocean had argued that because its drilling rig was portable and moved from one well site to another, it was a mobile vessel and not a stationary source. A Transocean spokeswoman says the company is evaluating the appellate court’s decision and had no further comment.

CSB continued to investigate the causes of the blowout and explosion during the appeal. In June, the board published its initial findings into how and why a safety device known as a blowout preventer was unable to stop the flow of hydrocarbons from the well. CSB expects to complete its inquiry early next year.