Following NELC’s successful lawsuits against Shell Oil Co. and Chevron Phillips Chemical Co. for illegal air emissions due to “upset” incidents, we continued our efforts to hold the fossil fuel industry accountable for poor air quality on Texas’s Gulf Coast by targeting the nation’s largest refining complex, ExxonMobil’s Baytown facility near Houston.
Due to equipment breakdowns, malfunctions, leaks, and operator errors, the Exxon complex routinely spewed unauthorized pollution into surrounding neighborhoods. We eventually proved that Exxon emitted over ten million pounds of illegal air pollutants – including known carcinogens, such as benzene and 1,3-butadiene, and known respiratory irritants, like hydrogen chloride and sulfur dioxide – during these “upset” incidents.
After losing an initial motion to dismiss the case, Exxon hired two new law firms and eight expert witnesses in preparation for what would has become a marathon 15-year legal battle. Following a three-week trial in 2014, the trial judge acknowledged Exxon’s violations but declined to penalize the company. The Fifth Circuit of Appeals, however, identified numerous errors of law and abuses of discretion in the trial court’s decision, which it instructed the judge to correct. On remand, the trial judge ruled in the citizen plaintiffs’ favor, finding that Exxon had committed over 16,000 Clean Air Act violations and assessing a $19.95 million penalty – the largest civil penalty imposed by a federal court in a Clean Air Act citizen suit. Exxon appealed this second trial court decision, and, after the Fifth Circuit again found deficiencies in the trial court’s reasoning, the penalty was reduced to a still record-setting $14.25 million on remand. This third decision went under review in the Fifth Circuit.
Stating that “justice delayed is justice denied,” in December 2024, a full en banc panel of 17 judges on the federal Fifth Circuit Court of Appeals rejected the attempt by ExxonMobil to avoid responsibility for violating a federal environmental law. The court affirmed a 2021 federal court ruling that found ExxonMobil committed more than 16,000 violations of the federal Clean Air Act at its Baytown, Texas, refinery and chemical plant complex. In March 2025, Exxon filed a fifth and final appeal to the U.S. Supreme Court.
In June 2025, the Supreme Court denied Exxon’s petition for a writ of certiorari, bringing fifteen years of litigation to an end. The $14.25 million penalty, which Exxon will pay to the federal government, is the largest ever imposed in a Clean Air Act citizen enforcement suit.
Exxon’s appeal sought to overturn the 25-year-old precedent in Friends of the Earth v. Laidlaw, which allows civil penalties to redress citizen injuries even without direct harm, and pushed for a more restrictive standard for proving that pollution-related injuries are “fairly traceable” to the defendant’s actions. These efforts aimed to alter the constitutional and statutory requirements governing standing in federal environmental cases in ways that would have made it harder for citizens harmed by illegal pollution to sue. The Court’s denial of certiorari ended these efforts.