United States v. Transocean Deepwater Drilling, Inc., 767 F.3d 485

On April 20, 2010, a blowout, explosion, and fire occurred during drilling at the Macondo lease site in the Gulf of Mexico, killing 11 and causing extensive environmental and property damage.
The Chemical Safety and Hazard Investigation Board (CSB) is an independent federal investigative agency created under the Clean Air Act Amendments of 1990, tasked with investigating accidental releases of hazardous substances into ambient air and issuing public reports and recommendations.
The CSB issued five administrative subpoenas to Transocean in connection with its Macondo investigation, seeking interrogatory responses and documents, including Transocean's internal investigation materials.
The district court ordered enforcement of the subpoenas, concluding that the CSB was investigating the release of airborne gases rather than a marine oil spill, and that the Deepwater Horizon drilling installation could satisfy the statutory notion of a stationary source.
Transocean argued the CSB lacked jurisdiction because the incident involved a vessel offshore and related maritime activity; the district court held the CSB had authority.
The court ultimately held that the CSB had jurisdiction to investigate the Macondo incident and enforce the subpoenas.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether CSB had authority under the Clean Air Act to treat the Macondo drilling installation as a stationary source.	Transocean contends the Deepwater Horizon is not a stationary source.	CSB contends the drilling installation was effectively stationary over the well.	CSB had jurisdiction to investigate as a stationary source.
Whether the marine oil spill exclusion bars CSB from investigating the Macondo incident.	Transocean argues CSB is precluded from marine oil spills by §7412(r)(6)(E).	CSB argues the exclusion is not all-encompassing and coordination with NTSB applies.	Marine oil spill exclusion did not categorically preclude CSB from investigating this incident.
Whether the NTSB had exclusive or concurrent authority to investigate the Macondo incident.	Transocean argues NTSB jurisdiction applied because the incident involved a vessel in navigation.	NTSB jurisdiction not applicable here; CSB may proceed.	NTSB lacked jurisdiction under §1131(a)(1)(F); CSB authorized to act.
Whether the CSB’s authority was limited by interagency coordination provisions mandating lead agency designations.	Transocean asserts the NTSB should be lead for transportation-related issues.	CSB must coordinate with NTSB and OSHA, but may investigate where appropriate.	CSB could investigate and enforce subpoenas consistent with interagency coordination.

Burlington Northern & Santa Fe Ry. Co. v. Office of Inspector General, 983 F.2d 631 (5th Cir. 1993) (enforcement standards for administrative subpoenas)
United States v. Powell, 379 U.S. 48 (1964) (limits of evidentiary burdens for subpoena enforcement)
Demette v. Falcon Drilling Co., 280 F.3d 492 (5th Cir. 2002) (mobile offshore rigs may be vessels under admiralty law)
In re Oil Spill by the Oil Rig 'DEEPWATER HORIZON' in the Gulf of Mexico, on April 20, 2010, 808 F. Supp. 2d 943 (E.D. La. 2011) (district court on vessel status and CSB jurisdiction post-disaster)
In re Deepwater Horizon, 745 F.3d 157 (5th Cir. 2014) (vessel status; maritime/administrative jurisdiction context)
Stewart v. Dutra Constr. Co., 543 U.S. 481 (U.S. 2005) (broad definition of vessels; maritime transportation)
U.S. Coast Guard v. Deepwater Horizon investigation report (coast guard materials cited), not a standalone reporter citation (2011) (contextual notes relied upon by majority regarding DP systems and vessel status)