On June 30, 2025, the U.S. Supreme Court declined to review a lower court judgment ordering ExxonMobil to pay a $14.25 million fine for over 16,000 violations of the Clean Air Act at its Baytown, Texas, refinery complex.
This means the lower court judgment stands and ExxonMobil must pay the penalty—a small sum for such a large corporation, but still the largest ever imposed in a citizen-initiated lawsuit under the Clean Air Act.
The outcome was a victory for Baytown area residents, and Environment Texas and Sierra Club, which sued ExxonMobil on behalf of those residents in a case that stretched over 15 years. The case has, during those 15 years, clearly impacted ExxonMobil’s emissions at the complex, one of the world’s largest such facilities. However, it’s equally clear that ExxonMobil must do more to reduce its emissions and protect the health of its neighbors.
To more fully understand what this case means for clean air, the people of Texas, and the ability of citizens to turn to the courts to enforce environmental laws, let’s focus our attention on the Houston Ship Channel area, traveling back in time to the beginning of this century.
Pollution linked to childhood leukemia, heart attacks and premature death
The Houston Ship Channel, which connects Houston, Galveston Bay and the Gulf of Mexico, is one of the world’s busiest waterways, providing a conduit for large ships carrying everything from Midwestern grains to the petrochemicals refined at one of hundreds of plants along the channel.
The pollution emitted by these refineries is among the reasons why the residents of this area breathe some of the most dangerous air in the country. Researchers have linked exposures to the industrial pollutants emitted in the area to asthma, childhood leukemia, other cancers, heart attacks, and premature death. On top of the threat to their health, residents in Baytown and surrounding communities have had to endure the stress of flaring events, toxic chemical leaks, massive industrial fires, and persistent foul odors.
Some of the pollution emitted by the refineries and other facilities in Texas is, like it or not, allowed by the government. Much of it, however, is not. For example, a report by Environment Texas Research & Policy Center and the Environmental Integrity Project found that in 2015, 679 industrial sites in more than 100 Texas counties released over 34,000 tons of air pollutants on 3,421 occasions, in what regulators call “unauthorized emission events.” The report’s findings were based on the industries’ self-reported data.
Despite the large amount of illegally emitted pollution, the agency responsible for enforcing clean air standards—the Texas Commission on Environmental Quality (TCEQ)—has compiled a poor record of enforcing the law. In December 2003, the Texas State Auditor released a report evaluating the permitting and enforcement programs at the TCEQ, concluding that the agency “does not consistently ensure that violators are held accountable” and that their penalty policies may not be effective “as a deterrent to polluters.” For example, the State Auditor found that “violators often have economic benefits that exceed their penalties, which could reduce their incentive to comply” with the law. (Almost twenty years later, in its review of TCEQ, the Texas Sunset Advisory Commission, whose members are appointed by the Speaker of the House and Lieutenant Governor, found that the agency continues to be a “reluctant regulator.”)
In response, in 2004, Environment Texas urged the commission to strengthen its enforcement program and penalty policy. Our staff met with TCEQ staff and commissioners, held a forum on the topic at the University of Texas Law School, gathered citizen petition signatures, and earned media coverage of the problem. Unfortunately, our efforts were unsuccessful.
Turning to ‘citizen suits’
With the government refusing to properly hold polluters accountable, Environment Texas turned to a provision of the Clean Air Act, which empowers citizens to sue polluters to compel them to comply with the law.
The Texas Legislature had, in 2001, passed a law requiring industrial facilities to self-report violations to the TCEQ (a compromise reached in response to a proposal to require mandatory penalties for violations). Under the 2001 law, violations were posted to a website, where the public could review them.
In 2007, after hearing from residents of Deer Park, Texas, about pollution problems at a nearby Shell oil refinery and chemical plant, our staff reviewed Shell’s self-reported violations and found clear evidence of illegal pollution.
We contacted attorneys at the National Environmental Law Center (a member, along with Environment Texas, of The Public Interest Network). NELC Senior Attorney Josh Kratka recommended that we take legal action on behalf of our members in the area. We invited the Sierra Club to join us in the suit, with the Club’s clean air program director, Neil Carman, offering valuable technical experience to the effort.
After reviewing our notice of intent to sue and meeting with our attorneys, Shell agreed to a landmark settlement: requiring the company to improve pollution controls, safety and monitoring at its Deer Park plant, and to pay a penalty for past violations. After the settlement, Shell reported a 95% reduction in unauthorized air emissions from flaring events at the facility.
Based on similar citizen complaints and a similar review of self-reported violations, we next took legal action against Chevron Phillips, winning a settlement that required pollution reductions, accident prevention, and stronger monitoring. Between the Shell and Chevron Phillips cases, the settlements helped reduce illegal air pollution in Houston by more than 1 million pounds per year.
In 2009, the Houston Chronicle called Environment Texas and the Sierra Club “the toughest enforcers of environmental laws” in Texas.
The Exxon case
Like Shell and Chevron Phillips, ExxonMobil had self-reported thousands of Clean Air Act violations to the TCEQ. Over an eight-year period, the company self-reported over 16,000 violations at its Baytown Complex, resulting in 10 million pounds of unauthorized air pollutants, including cancer-causing chemicals and respiratory irritants. Yet the TCEQ only imposed fines for 36 of those violations.
So in 2010, working again with Sierra Club and NELC, we filed notice of our intent to sue ExxonMobil.
Our case was strong. On average, ExxonMobil had self-reported, on average, more than one excessive emission event each day for eight consecutive years. For example, on October 16, 2010, a broken hose released into the air more than 15,000 pounds of chemical pollutants, most of them toxic or carcinogenic, in just 30 minutes. The same day, an underground pipe began to leak, and Exxon did not shut it down for 28 hours, until more than 50 tons of volatile organic compounds and 81 pounds of benzene escaped into the air.
Baytown resident Marilyn Kingman lamented: “Exxon is emitting all of these day after day. Anybody who lives in the Baytown area is suffering.”
Despite the clear evidence of violations and the resulting health threats posed to people in the area, ExxonMobil declined to negotiate a settlement. However, after we filed our case, the company upgraded pollution controls at its Baytown facility. ExxonMobil’s emissions declined by 82%, from an average of approximately 2.3 million pounds per year from 2004 to 2009 to about 413,000 pounds per year from 2010 to 2015.
However, ExxonMobil had not legally bound itself to pollution reductions and other steps to improve the air and quality of life for its Baytown neighbors. Nor did it agree to pay any penalty for its past violations. After consulting with our Baytown plaintiffs, we decided to keep pursuing the case.
A three-week trial
Rather than settle, ExxonMobil came up with its own punishment. As I wrote in a 2013 Houston Chronicle op-ed, TCEQ’s former chief of enforcement testified at his deposition that Exxon actually wrote the first draft of this agreed order, and had significant input into any changes the agency tried to make to it. TCEQ then issued an enforcement order that could potentially shield the company from further accountability. Citizen suits can sometimes be derailed in the courts when an agency takes enforcement action. We went to trial in February 2014 before Judge David Hittner.
The trial lasted three weeks. Baytown resident Shae Cottar pulled out his phone while on the witness stand to show Judge Hittner photos he had taken of smoking flares that ruined a family outing. Other residents described windows rattling from flaring events, sooty fallout and foul odors that forced them indoors.
Despite the evidence we presented, Judge Hittner ruled against us after trial, declining to impose penalties or to require Exxon to stop breaking the law.
The appeals
We appealed to the federal Fifth Circuit Court of Appeals. In 2016, a unanimous three-judge panel ruled that Judge Hittner had “erred in [his] analysis” and “abused [his] discretion.” The judges agreed that in Judge Hittner’s rulings, he ignored the seriousness of major pollution releases because they were somehow balanced out by numerous instances of illegal emissions that were smaller in amount and duration. The appeals court “remanded” the case back to Judge Hittner for correction of the legal errors, and a new determination regarding the number of violations proven and the amount of penalties to be imposed. To his credit, Judge Hittner scrupulously followed the Fifth Circuit’s order and assessed a nearly-$20 million penalty, later reduced to $14.25 million after excluding certain violations.
Then ExxonMobil appealed. In two separate rulings, sandwiched around yet another remand of the case to Judge Hittner to make more detailed factual findings, the same three-judge panel of Fifth Circuit judges rejected virtually all of ExxonMobil’s legal challenges and reaffirmed the penalty.
Next, ExxonMobil requested a rarely granted “en banc” review of its appeal, to be heard by all 17 judges of the Fifth Circuit. The Houston Chronicle editorial board weighed in, urging the court to uphold Judge Hittner’s ruling. The board called the case “a victory for Texans who want to breathe clean air, for communities burdened by the petrochemical industry’s pollution and for the principle that companies, no matter how big, must follow the law.” The editorial emphasized that “citizen lawsuits play a vital role in enforcing environmental laws when state regulators fail to act.” In a front page story, the Washington Post noted that, if Exxon were successful, it “could weaken ordinary Americans’ ability to sue industrial polluters across the country.”
In December 2024, in a major win for public health and corporate accountability, the full 17-judge Fifth Circuit Court ruled against Exxon.
The final appeal
ExxonMobil still refused to settle. Instead, the company appealed the case to the U.S. Supreme Court. ExxonMobil’s argument: The lower courts had erred in not setting a much tougher standard for proving that ExxonMobil’s pollution harmed or threatened to harm the people in Baytown. In fact, the company argued that the people should have to prove that every specific emission caused a separate specific injury—a much more stringent, and much more difficult to prove, standard than the law requires and that courts had affirmed for decades.
The Supreme Court, however, declined to hear ExxonMobil’s appeal. The right of citizens harmed by pollution to sue the offending polluters under the Clean Air Act still stands, ensuring that Texans and regular people nationwide can continue to enforce their legal right to clean air when government regulators aren’t doing their jobs.
An imperfect but important victory
In a perfect world, ExxonMobil would be doing all it could to not only comply with the Clean Air Act at its Baytown Complex and all of its refineries, pay penalties for any violations, and spend even more to mitigate the damage caused to people’s lives and environment—but it would also be working to go beyond the law’s requirements and reducing its pollution even more.
In the real world we live in, ExxonMobil seeks to expand its Baytown Complex and remains one of the top polluters in the Houston area. And, of course, a company the size of ExxonMobil will have no problem paying a $14.25 million fine.
However, as market research firm FMP notes, the “precedent and reputational optics [of the case] may carry broader consequences for Exxon” and “judicial momentum is swinging toward environmental accountability, even in energy-dominant states like Texas.”
Companies large and small must still be mindful of the fact that, under the Clean Air Act and the Clean Water Act, ordinary citizens may initiate legal action to compel their compliance with limits on air and water pollution. When necessary, Environment Texas, along with our partners at the National Environmental Law Center and on behalf of the people of Texas, remain ready to take action.
Authors
As the executive director of Environment Texas, Luke is a leading voice in the state for clean air and water, parks and wildlife, and a livable climate. Luke recently led the successful campaign to get the Texas Legislature and voters to invest $1 billion to buy land for new state parks. He also helped win permanent protection for the Christmas Mountains of Big Bend; helped compel Exxon, Shell and Chevron Phillips to cut air pollution at four Texas refineries and chemical plants; and got the Austin and Houston school districts to install filters on water fountains to protect children from lead in drinking water. The San Antonio Current has called Luke “long one of the most energetic and dedicated defenders of environmental issues in the state.” He has been named one of the “Top Lobbyists for Causes” by Capitol Inside, received the President’s Award from the Texas Recreation and Parks Society for his work to protect Texas parks. He is a board member of the Clean Air Force of Central Texas and an advisory board member of the Texas Tech University Masters of Public Administration program. Luke, his wife, son and daughters are working to visit every state park in Texas.
