CSB has authority to investigate Deepwater Horizon, court affirms

New Orleans – The Chemical Safety Board has the authority to investigate the 2010 Deepwater Horizon explosion in the Gulf of Mexico, the U.S. Court of Appeals for the Fifth Circuit affirmed in a ruling issued Sept. 18.

The owner of the Deepwater Horizon oil rig, Transocean Deepwater Drilling, appealed a 2013 district court order requiring the Swiss-based offshore drilling contractor to comply with CSB-issued subpoenas. Transocean argued that CSB lacks the authority to investigate because the incident was a marine oil spill occurring on a non-stationary source.

In a 2-1 decision, the Appellate Court agreed with the district court’s finding that CSB was investigating the airborne gas release from the explosion – not the oil spill – and the rig met the statutory requirement of a “stationary source.”

“The Court’s decision follows an extensive litigation effort by the CSB and the Justice Department, and affirms what the CSB has consistently maintained – that the CSB has the legal authority to thoroughly investigate the Gulf tragedy,” CSB Chairman Rafael Moure-Eraso said in a statement.

Eleven workers were killed in the explosion. CSB began investigating the blast shortly after it occurred, and the agency has released volume one and two of its four-volume report on the incident.