In Re: Methyl Tertiary Butyl Ether Products Liability Litigation

Background

This case is part of a consolidated multidistrict litigation concerning groundwater contamination caused by releases of gasoline containing methyl tertiary butyl ether, or MTBE. The Commonwealth of Pennsylvania alleges that dozens of gasoline manufacturers, distributors, and sellers are liable for actual or threatened MTBE contamination in Pennsylvania drinking water.

Pennsylvania moved for partial summary judgment on defendants’ affirmative defenses—legal defenses that defendants raise to avoid or limit liability. The motion covered 70 Focus Sites in the first phase of the case and sought judgment on estoppel, assumption of risk, waiver, comparative negligence, and unclean hands. The defendants did not oppose judgment on waiver, comparative negligence, and unclean hands. Estoppel and assumption of risk remained disputed.

Estoppel

The defendants argued that Pennsylvania should be barred from seeking future costs or injunctive relief concerning 22 sites because Pennsylvania’s Department of Environmental Protection had approved remedial action completion reports for those sites. They contended that they removed equipment and abandoned groundwater-monitoring wells in reliance on the approval letters and on an understanding that they would not have to perform or pay for additional work.

Applying Pennsylvania law, the court explained that equitable estoppel generally requires misleading words, conduct, or silence; reasonable reliance; and the absence of a duty to inquire. When estoppel is asserted against the government, the party asserting it must provide clear, precise, and unequivocal evidence that the government intentionally or negligently misrepresented a material fact, knew or should have known the other party would rely on it, and induced detrimental reliance.

The court rejected the defense. The approval letters did not expressly promise that defendants would never have to perform or pay for future remedial work, and the defendants identified no facts showing that Pennsylvania intentionally or negligently misrepresented a material fact. The letters therefore were not clear, precise, and unequivocal evidence of such a promise. The court also stated that Pennsylvania law disclaims treating approval of a remedial action completion report as a release from civil or criminal liability, and that the letters did not shield defendants from all claims for further damages.

Assumption of Risk

The Commonwealth argued that Pennsylvania law does not recognize assumption of risk in negligence actions. The court declined to decide whether the defense is completely unavailable. It concluded that, at least in limited circumstances, Pennsylvania law permits the defense in negligence cases. The defense may apply when a plaintiff deliberately and voluntarily encounters a specific risk while aware of it, or when the plaintiff knew of a dangerous condition that was obvious and avoidable but voluntarily faced it.

The defendants argued that Pennsylvania assumed the risk of MTBE contamination by not banning MTBE, not fully implementing an MTBE action plan, adopting corrective-action regulations, and overseeing cleanup at particular release sites. The court held that these facts, even when viewed in the defendants’ favor, could not support the defense. A government’s failure to prohibit an activity does not mean it assumed the risk of every consequence of that activity. Similarly, creating or failing to create a regulatory cleanup process does not provide a general defense to liability, and a regulatory safe harbor under some laws does not protect against liability under all other laws.

The court also found that the defendants did not explain what factual disputes their evidence created or how Pennsylvania’s awareness of MTBE’s risks showed that it voluntarily proceeded to face those risks. The defendants cited no Pennsylvania authority supporting their theory that regulatory activity displaced tort liability in these circumstances.

Disposition

Judge Denise Cote granted the Commonwealth’s February 25, 2025 motion for partial summary judgment as to defendants’ affirmative defenses. The opinion’s conclusion states that the motion was granted; it does not add a with-prejudice or without-prejudice qualifier.