The bad news for BP just keeps coming from the U.S. Court of Appeals for the Fifth Circuit. On Wednesday, the court held that BP Exploration & Production Inc. can be liable for enormous statutory damages under the Clean Water Act as a co-owner of the Macondo well that polluted the Gulf of Mexico in 2010. The unanimous panel also ruled that codefendant Anadarko Petroleum Corp., which owned a minority interest in the well, is also liable. BP could be assessed as much as $18 billion in fines, and Andarko could be fined $4.6 billion.

The fines will be set by New Orleans U.S. District Judge Carl Barbier, with the amount depending in part on whether he finds the companies were grossly negligent. BP is represented by Richard Godfrey of Kirkland & Ellis, and Anadarko is represented by David Salmons of Bingham McCutcheon. The DOJ’s lead lawyer for this appeal is Steven O’Rourke.