President Donald Trump has issued an executive order titled “Regulatory Relief for Certain Stationary Sources to Promote American Energy,” granting a two-year extension for compliance with stricter emissions standards under the Environmental Protection Agency’s (EPA) Mercury and Air Toxics Standards (MATS). The executive order is part of the administration’s broader effort to bolster domestic coal production.

The proclamation delays compliance with an EPA rule finalized on May 7, 2024, which imposed more stringent emissions controls on coal- and oil-fired power plants. 

The updates to the EPA’s Mercury and Air Toxics Standards (MATS) were based on new findings about the remaining risks from power plant pollution (“residual risks”) and improvements in pollution control technology. Here’s what changed:

Stricter Emissions Limits

• Mercury Emissions: The rule significantly tightened the limit on mercury emissions for lignite-fired power plants (a type of coal plant), reducing allowable emissions by 70%. 
• Particulate Matter (PM): The rule also imposed stricter limits on filterable particulate matter (tiny particles released during combustion), reducing the allowable amount by 67%. This change indirectly controls other toxic pollutants like arsenic, chromium, nickel, and cadmium, which are often carried by these particles.

In order to show compliance with the rule, power plants would be required to use Continuous Emissions Monitoring Systems (CEMS) to measure particulate matter emissions in real time. This would ensure that plants consistently meet the new standards rather than relying on occasional testing.

The EPA anticipated that 33 coal-fired units would need to upgrade their pollution control technologies to meet the revised limits.

Trump’s executive order means that coal- and oil-fired power plants will instead adhere to the 2012 Mercury and Air Toxics Standards. 

While the 2012 standards had already reduced mercury emissions by 90%, acid gas hazardous air pollutants (HAPs) by over 96%, and non-mercury metals by more than 81%, the 2024 revisions further tightened these limits and introduced new measures to address remaining risks. 

By cutting hazardous air pollutants further, the new standards were projected to prevent up to 1,200 premature deaths annually by 2035. Mercury, a neurotoxin that can cause severe developmental harm, particularly in children and pregnant individuals. The new regulations were expected to avoid thousands of cases of asthma, hospital visits, and missed school or workdays. 

The 2024 MATS rules were set to take effect on July 8, 2027, but the new order extends the deadline to July 8, 2029. 

The proclamation warns that enforcing the original timeline could lead to widespread shutdowns of coal-fired power plants, jeopardizing thousands of jobs, increasing electricity costs, and threatening national energy security. 

While Trump campaigned on promises to revive coal and took steps to roll back environmental regulations during this first term from 2017-2021, the industry continued its long-term decline due to market forces and structural changes in the energy sector. 

No significant new coal plants were built during Trump’s first term because of a decade-long trend, with nearly 40% of U.S. coal capacity shutting down over the past decade. Utilities increasingly opted for cheaper and cleaner alternatives like natural gas and renewable energy, making coal plants economically unviable.

Trump rolled back several Obama-era environmental regulations, including rules on carbon emissions and water pollution from coal plants, in an attempt to reduce costs for the industry. His administration sought to subsidize coal plants through federal energy regulators, but these efforts were largely unsuccessful due to opposition from regulators and market realities.

Coal’s share of U.S. electricity generation fell below 20% during Trump’s first term, compared to over 50% in the early 2000s.