For more than a quarter century, Shirley Williams has tended to her backyard garden at her home in Baytown, Texas. Behind her house grow two orange trees, a pear tree, and a crepe myrtle.  

She and her husband, a disabled military veteran, bought the house with plans to live there the rest of their lives.  

But looming over her back fence are stacks and flares from ExxonMobil’s Baytown Refinery that belch flames and black smoke, reminding her of a “dragon’s head.”  

Though the facility has grown over the years, ExxonMobil has avoided updating some of the refinery’s most heavily-polluting pieces of equipment.  Soot from the refinery often coats the outside of her home and many of the neighbors suffer from asthma, cancer, and other health issues, she said.  

“Why do people have to live with this?” Williams asked as flames from the refinery licked up into the sky. “I think they should practice being better neighbors,” she said of ExxonMobil.

Of the 20 biggest greenhouse gas polluters among refineries in the U.S., ExxonMobil’s Baytown Refinery has the highest number of outdated heaters and boilers – which is a problem, because outdated boilers tend to be less efficient and release more pollution, according to an analysis by the Environmental Integrity Project.  

Eighty-three of the ExxonMobil refinery’s 125 boilers are older than 15 years, the point at which industry experts consider them to be outdated, and at least one furnace at the refinery is at least a half-century old.

The Environmental Integrity Project (EIP) examined publicly available data and records for the 20 petroleum refineries in the U.S. that reported emitting the most greenhouse gases in 2023. Of the refineries whose boilers had age information, 87 percent of those units (739 of 845) are outdated, the group found.  

While experts have concluded that boilers and heaters work most efficiently when they are 15 years old or younger, the average age of the heating systems in the largest refineries is more than 40 years old. The oldest refinery boiler that EIP found dated to 1948, with the oldest heater installed in 1939.  

Refineries use boilers to produce steam, which can then be used to generate energy or for its own heat. Heaters and furnaces are used to concentrate certain petrochemical products or break larger molecules into smaller molecules. All this equipment becomes less efficient as it ages.  

Overall, the 20 refineries EIP examined released more than 82 million metric tons of greenhouse gases in 2023. That’s as much as 22 coal-fired power plants operating around the clock, or 19 million cars and trucks running for a year.

These refineries also reported emitting 80,981 tons of health-damaging “criteria” air pollutants in 2020, including microscopic soot particles that can trigger asthma and heart attacks. And they emitted 6.9 million pounds of hazardous air pollutants (some of which, like benzene, are carcinogens).  

An estimated 43 percent of the criteria pollutants, 16 percent of greenhouse gases, and five percent of hazardous air pollutants came from the heaters, boilers, or furnaces at the refineries. This is likely an underestimate due to gaps in publicly available data, according to EIP’s analysis.

ExxonMobil’s Baytown Refinery was one of six out of the 20 EIP examined that have been flagged by the EPA as having an unresolved “high priority violation” of the Clean Air Act for at least the last three years, according to EPA’s Enforcement and Compliance History Online database.  

ExxonMobil paid $176,000 for six enforcement actions over the last five years, according to the EPA database.  But that was not even a slap on the wrist for a company that reported earning $33.7 billion in profits in 2024.  

The refineries’ violations often harm lower-income neighborhoods and people of color living near the industry.  About 70 percent of the refineries examined by EIP (14 of 20) are located in what EPA considered disadvantaged communities, according to EPA’s Environmental Justice screening tool.  

In Deer Park, southeast of Houston, a massive refinery owned by Mexican national oil company Pemex spews air pollution less than a quarter mile from the nearest homes. All of the refinery’s 36 boilers are outdated, according to EIP’s analysis.  

In a neighborhood just across a highway from the Pemex refinery, Camden Gothia, 53-year-old former chemical plant worker, has lived on Second Street in Deer Park, for 15 years. He said he frequently smells chemicals in the air and sees the orange glow of flares lighting up the sky for weeks.  

“Of course they should update their boilers,” Gothia said, adding that regulatory agencies “should absolutely require that.”

Two-thirds of the refineries (13 of 20) examined by EIP are located in areas that EPA has designated has having unsafe levels of smog, or ground-level ozone pollution. Ozone forms when nitrogen oxides (mainly from fuel burning) interact in the presence of sunlight with volatile organic compounds, which in industrial areas often come from refineries and chemical plants. Exposure to unsafe levels of ozone can cause respiratory problems, such as shortness of breath, asthma attacks, and increased risk of respiratory infections.  

Heaters and boilers contribute the majority of greenhouse gas emissions in several refineries EIP examined that had available data.  The most severe example is Motiva Enterprises in Port Arthur, Texas, where heaters and boilers account for 84 percent of such emissions.  

An EPA paper suggests that refineries could cut pollution and improve energy efficiency by upgrading old boilers or replacing them with modern technology. Some smaller boilers could be replaced with zero-emitting electric pumps, according to a 2024 report from the American Council for an Energy-Efficient Economy.  

Even modest reductions in air pollution would be a relief for people who live around oil refineries and complain that the emissions significantly harm their quality of life.

Jorge Guerra, 55, who has lived in Second Street in Deer Park, near the Deer Park refinery, for about 20 years, said he suffers eye and nose irritation from the soot, air pollution, and foul odors from the refinery and is sometimes kept up by its loud flaring.

“Absolutely, the federal government needs to intervene,” Guerra said. “If the federal government did not intervene, we’d all still be working 80 or 90 hour weeks… They need to monitor more heavily in our residential area to make sure we are not living or working in a war zone or danger zone.”

Savannah Sadaiappen, 26, grew up in Norco, Louisiana, near another refinery examined by EIP that has outdated heaters and boilers, the Shell Norco refinery.  She said she worries about the health impacts of all the smoke she sees being released by the refinery, including on rates of asthma and cancer, and thinks government should push refineries to modernize and reduce their pollution.

“That’s what the government is there for, to serve us and make sure we are healthy and to make sure these big corporations are operating safely,” said Sadaiappen, a medical student. “I think EPA should have some stricter regulations for [refineries]…or maybe give them benefits to upgrade their equipment.”

Lead photo: ExxonMobil's Baytown Refinery, which has the most outdated boiler and heaters of the 20 facilities included in a recent review. Photo by Garth Lenz/Flight SouthWings.