On September 4, 2015, the United States Court of Appeals for the Fifth Circuit overturned Citgo Petroleum Corporation’s two convictions under the Clean Air Act (CAA) and three convictions under the Migratory Bird Treaty Act (MBTA).  The court held that the district court had erred in allowing improper jury instructions and had misinterpreted the MBTA’s “take” provision.  

The Convictions

Citgo’s convictions stem from allegations of an impermissible wastewater treatment program at its Corpus Christi oil refinery.  United States of America v. Citgo Petroleum Corporation, et al., No. 14-40128, 2015 WL 5201185, at *2 (5th Cir. Sept. 4, 2015).  Oil refinery wastewater, comprising “a mixture of solids, sludges, and oil,” is subject to regulation under both the Clean Air Act and the Clean Water Act due to potential health risks.  Id. at *1.  To reduce these health risks, wastewater is funneled into water-oil separators.  In these separators, oil rises to the surface, where it can be removed by the refinery.  Id. at *1.  The wastewater then flows into equalization tanks, where it is stored before undergoing subsequent treatment.  Id. at *2.

Texas officials found a large volume of oil within two of Citgo’s uncovered equalization tanks, which led them to conclude that Citgo was using the tanks as water-oil separators.  Id.  Such a configuration is impermissible under the CAA, which requires water-oil separators—but not equalization tanks—to be covered.  The central issue for the district court jury was whether Citgo’s equalization tanks constituted water-oil separators.  Finding they did, the jury convicted Citgo of violating the CAA by operating water-oil separators without proper emission control.  Id.  The jury handed down one conviction for each of the two uncovered equalization tanks that they Citgo used as water-oil separators.  Id.  The jury also convicted Citgo on three counts under the MBTA based on suspicion that migratory birds had died in the uncovered equalization tanks.  Id.

The Fifth Circuit’s Reversal

Clean Air Act

The Fifth Circuit overturned both of Citgo’s convictions under the CAA.  The court based the reversals on harm caused by the district court’s jury instructions.  In particular, the court rejected the jury instructions’ claim that a water-oil separator “is defined by how it is used.”  Id. at *3.  The Court found this “purely functional” explanation inconsistent with the text of the CAA regulations, which “define[] an oil-water separator by how it is used and by its constituent parts.”  Id.  The court further noted that the “purely functional” explanation was inconsistent with other wastewater treatment regulations.

Because the Clean Air Act case against Citgo turned entirely on whether Citgo used its equalization tanks as water-oil separators, the Fifth Circuit held that the improper definition of a water-oil separator “undoubtedly affected the verdict.”  Id.  This error alone, the court held, was sufficient to warrant reversal of all CAA conviction.  Id.

Migratory Bird Treaty Act

The Fifth Circuit similarly overturned both of Citgo’s convictions under the MBTA, citing the district court’s erroneous definition of the word “take.”  The MBTA holds that it is “unlawful at any time, by any mean or in any manner, to pursue, hunt, take, capture, kill, attempt to take, capture, or kill…any migratory bird[.]”  16 U.S.C. § 703(a); § 704(a).  The district court adopted an expansive view of the word “take,” holding that it is a “term that involves more activities than those related to hunting, poaching and intentional acts against migratory birds.”  United States v. Citgo Petroleum Corp., 893 F. Supp. 2d 841, 842-43 (S.D. Tex. 2012) rev’d, No. 14-40128, 2015 WL 5201185 (5th Cir. Sept. 4, 2015).  This interpretation of “take” supported Citgo’s conviction of “taking” migratory birds by leaving its equalization tanks uncovered, theoretically allowing birds to enter the tanks and die from exposure to the wastewater within.

The Fifth Circuit rejected this interpretation, instead adopting the Eighth and Ninth Circuits’ reasoning that a taking “is limited to deliberate acts done directly and intentionally to migratory birds.”  Citgo, 2015 WL 5201185, at *9.  The court found persuasive Justice Scalia’s application of a taking to animals: “As applied to wildlife, to ‘take’ is to ‘reduce those animals, by killing or capturing, to human control.’”  Id. at *10, citing Babbitt v. Sweet Home Chapter Cmtys for a Great Or., 515 U.S. 687, 717 (1995) (Scalia, J., dissenting).  Rejecting the government’s position that “take” has a wider range of meanings that could encompass an accidental taking, the court noted that “One does not reduce an animal to human control accidentally or by omission; he does so affirmatively.”  Id.

In adopting this definition of “take,” the court declined to adopt the Second and Tenth Circuits’ interpretation of the MBTA.  Those circuits have held defendants criminally liable under the MBTA for unintentional killing of birds, reasoning that the MBTA is a strict liability statute, so unintentional killings still constitute criminal activity.  Id. at *13.  The Citgo district court had applied this reasoning, holding that Citgo was criminally liable under the MBTA because it was “obvious” that “unprotected oil field equipment can take or kill migratory birds.”  Id., citing Citgo, 893 F. Supp. 2d at 847 (quoting United States v. Apollo Energies, 611 F.3d 679, 868 (10th Cir. 2010)).  The Fifth Circuit rejected this argument, noting that Citgo was convicted of “taking” under the MBTA, not the separate “killing” provision.  The court reasoned that “the act is ‘to take’ which, even without a men rea, is not something that is done unknowingly or involuntarily.”  Id.


While finding that Citgo had no liability under the Clean Air Act or Migratory Bird Treaty Act, the Fifth Circuit took this case as an opportunity to issue a stern warning.  The court detailed the absurd consequences of adopting an expansive view of the “taking” and “killing” provisions of the MBTA.  Each year in the United States, hundreds of millions of birds lose their lives in run-ins with windows, communication towers, domesticated cats, wind turbines, solar energy farms, cars, and church steeples.  Id. at *14.  An expansive view of the MBTA could criminalize the owners of any object or pet that kills a bird, opening the door to criminal liability for many—if not most—Americans.  Id.

Although the Fifth Circuit’s warning has elements of absurdity, the warning should not be dismissed entirely: both the Second and Tenth Circuits have already convicted corporate entities under the MBTA for unintentional bird deaths.  Convictions under the MBTA can carry sentences of six months imprisonment and fines up to $15,000.  16 U.S.C. § 707(a).  While Citgo escaped liability under MBTA, corporations in other circuits will find the law to be less forgiving.