April 10 (Reuters) - Barbara Johnson has been fighting coal pollution for decades in her mostly Black neighborhood of North St. Louis as an organizer with Metropolitan Congregations United – one of many activist groups campaigning for cleaner air in a city that has some of the country’s dirtiest.
Until recently, Johnson had reason to believe things would improve: tougher federal soot standards adopted in 2024 under the Biden administration were scheduled to go into effect in 2027, requiring plants to slash emissions or shut down. That would have forced one of the area’s biggest polluters - Ameren’s Labadie Energy Center power plant - to cut its soot emissions in half to stay in business.
Johnson’s hopes vanished in February, however, when President Donald Trump’s administration scrapped the standards before they took effect as part of broader efforts to ensure the nation’s grid can meet surging demand from data centers. Now she wonders if she’ll ever get to see the changes she’s been fighting for since her youth.
"You take two steps forward and four steps back," said Johnson, 75. "I am used to that backwards trend but how many generations will it take to make those positive changes stick?"
Trump’s rollbacks in support of AI mark a reversal in U.S. environmental policy and a painful truth for America's clean air activists: After years pushing coal toward the exits, the rise of power-hungry data centers has nudged the country's most polluting power source back to the stage.
Trump last year issued an executive order entitled "Reinvigorating America’s Beautiful Clean Coal Industry" that said coal-fired power was crucial to meeting the rise in U.S. electricity demand driven by the construction of artificial intelligence data processing centers. He has since provided funding to keep old plants running, issued orders to delay plant retirements, and rolled back environmental regulations on mercury and other toxins to free plants from costly upgrades.
"Ensuring affordable baseload power, including coal, is essential for keeping the lights on and heating American homes," the U.S. Environmental Protection Agency said in an emailed statement about the regulatory rollbacks. "EPA is committed to ensuring clean air for all Americans regardless of race, gender, creed, or background."
The U.S. Department of Energy estimates artificial intelligence and data‑center growth will create 50 gigawatts of new electricity demand by 2030 – a nearly 4% increase over the 1,300 gigawatts produced by all U.S. power plants in 2025.
Reuters interviewed 20 air quality activists and health advocates for this story and found all had identified the AI boom - and the policies supporting it - as the biggest potential threat to U.S. air quality due to its need for power, including from dirty sources like coal.
Over the past decade, the number of U.S. coal plants providing energy to the grid and other industrial operations dropped to about 200 from nearly 400 in 2015, according to EPA data examined by Reuters. But that pace has slowed fast.
In 2025 only four plants producing 2.6 gigawatts were retired, compared with 94 producing 15 gigawatts in 2015, as the DOE issued emergency orders keeping them online, according to the U.S. Energy Information Administration.
A coalition of farmers, environmentalists and homeowners have united to resist data-center expansion out of concern for its impacts, ranging from higher power bills to reduced water supplies - a potential liability for Republicans in the November midterm elections.
Trump has since secured voluntary agreements from big tech companies to pay up for their power needs and shield American consumers from higher bills, but his administration has not announced steps to address the health effects of higher pollution from expanded power generation.
St. Louis will be among the U.S. cities most impacted by the regulatory rollbacks, mainly because of its already poor air quality and the close proximity of the huge Labadie plant, according to the interviews, and government data reviewed by Reuters.
Last year, metro St. Louis residents had "good" air to breathe during only one-third of the days of the year, according to the standards used by the EPA’s Air Quality Index. That ranked St. Louis 475th in air quality out of 501 small and large U.S. metro areas.
The Labadie Energy Center is a significant contributor, according to EPA data and recent scientific studies.
The plant, a sprawling facility that sits around 40 miles to the city’s west, produces the highest combined total of sulfur dioxide and nitrogen oxides among U.S. coal plants, and also emits soot at a rate that is two to three times that of nearly every other U.S. coal plant, according to EPA data.
That pollution drives an estimated economic burden of up to $5.5 billion each year, with about $820 million of those costs borne by St. Louis area residents, according to a Reuters analysis of the EPA’s Co-Benefits Risk Assessment (COBRA) tool.
COBRA estimates health costs such as emergency room visits and measures how much people, collectively, are willing to pay for cleaner air because it lowers the risk of premature death.
Reuters showed the analysis to two outside experts - Bryan Hubbel, a senior fellow at non-profit research group Resources for the Future and John Graham, a senior scientist at the environmental research group Clean Air Task Force - who both agreed with the figures.
Labadie’s owner, St. Louis-based utility Ameren Corp, did not contest the Reuters analysis of the EPA data.
Ameren said the plant operates within the existing federal pollution limits. Labadie will keep running for at least another decade as demand from artificial intelligence-driven data centers outpaces the rollout of cleaner power, Ameren said.
"Our employees live here, raise families here and rely on the same energy as our neighbors," Craig Giesman, Ameren's director of environmental services, said in a statement. "That is just one of many reasons we remain focused on operating responsibly, protecting public health and providing reliable energy, especially when it’s needed most."
The EPA declined to comment on Reuters’ analysis of the COBRA data, but pointed out the agency is seeking to update its cost-benefit modeling tools.
A scientific study led by researchers at the University of Washington and published in the Journal of the International Society for Environmental Epidemiology last year said St. Louis would be the city most impacted by delaying tougher soot standards on U.S. coal plants.
Biden’s regulation would have forced Labadie to slash its soot emissions by more than half to continue to operate. Those soot limits would have yielded net public health benefits of up to $3 billion nationwide by 2037, according to the EPA’s 2023 cost-benefit analysis.
The EPA under Trump has since reversed course. The agency told Reuters the Biden administration’s estimates were overblown and that existing standards provide "an ample margin of safety to protect public health."
St. Louis clean air activists see it differently.
"Our region continues to be a sacrifice zone," said Darnell Tingle, director of United Congregations of Metro-East, another activist network. "We are trying to prepare for these data centers, and negate their harm to our communities."
CHEAP POWER
The predominantly Black neighborhoods of North St. Louis already have some of the city’s worst air quality. Tiny particles of soot pollution small enough to penetrate the brain and lungs exceed federal safety limits there regularly, according to a Reuters analysis of data tracked by the EPA, thanks to industrial sources along with pollution from nearby highways and rail operations.
Some 78% of African Americans live within 30 miles of a coal-fired power plant, according to the NAACP, compared to 56% of non-Hispanic whites. Soot pollution from power plants, meanwhile, kills African Americans at a rate that is 25% higher than the national average, according to a 2019 study in the Environmental Science & Technology journal.
"The logic is that we need cheap electricity in the U.S. But if you look at the rise in healthcare costs for residents in the St. Louis area, this isn’t cheap," said Patricia Schuba, who runs a local environmental group that monitors Labadie and three other coal plants.
Tougher pollution limits had forced Ameren to upgrade Labadie. About a decade ago, Ameren installed state-of-the-art soot pollution controls for two of Labadie’s four coal-fired boilers in order to comply with Obama-era soot limits.
At a minimum, older controls on the remaining boilers would have needed retrofitting to meet Biden‑era limits, Ameren told the EPA in a March 2025 letter seeking an exemption. Ameren declined to answer questions about how much upgrading the plant would have cost.
Meanwhile, data‑center developers are breaking ground on major projects around St. Louis, pushing up regional electricity demand.
Ameren has said it has signed service contracts for an additional 2.3 gigawatts of potential peak demand from data centers – roughly the output of the Labadie plant – and that more requests are coming. One of the biggest upcoming data center projects is a 1,000-acre development by Amazon Web Services proposed for rural Montgomery County, about 55 miles from Labadie. The power would be supplied by Ameren.
Amazon declined to comment.
The data center industry’s trade group - the Data Center Coalition - said its member companies were among the top purchasers of clean energy but that utilities, regulators and grid operators are ultimately responsible for the kinds of power generation being used by consumers.
"While the data center industry is leaning in to support the development of the 21st-century electrical grid, it’s important to recognize that resource planning and generation procurement decisions are made by utilities, grid operators, and policymakers, not large load customers like data centers," said Lucas Fykes, Senior Director of Energy Policy and Regulatory Counsel at the coalition.
(Reporting by Valerie Volcovici and Tim McLaughlin; editing by Richard Valdmanis, Michael Learmonth and Frank Jack Daniel)
