US environment agency to weaken rule limiting harmful mercury, air toxics from coal plants

WASHINGTON – The Trump administration announced on Feb 20 it will roll back air regulations for power plants limiting mercury and hazardous air toxics at an event in Kentucky.

It said this would boost base-load energy, but public health groups insisted it would harm public health for America’s most vulnerable groups.

The Environmental Protection Agency (EPA) has said easing the pollution standards for coal plants will alleviate costs for utilities that run older coal plants at a time when demand for power is soaring amid the expansion of data centres used for artificial intelligence.

But environmental groups have said weakening standards for mercury – a neurotoxin that can impair babies’ brain development – and other air toxics will lead to higher health-related costs.

The Mercury and Air Toxics Standard (MATS) approved under former president Joe Biden, which updated standards set in 2012 under the Obama administration, had still been in force after the Supreme Court declined to put the rules on hold after a group of mostly Republican states and industry groups led a legal challenge to suspend it.

That rule would reduce allowable mercury pollution from the coal plants by 70 per cent, emissions of nickel, arsenic, lead and other toxic metals from coal plants by  two-thirds and result in health cost savings of US$420 million (S$533 million) through 2037, according to the Environmental Defence Fund.

The EPA said in a statement on Feb 18 that the 2012 MATS rule provides “an ample margin of safety to protect public health”, and that its proposed 2024 additions would cost more than they benefit.

Utilities have been phasing out ageing coal-fired generators, which are major sources of mercury and carbon emissions, but President Donald Trump has promised to reduce barriers to meet rising electricity demand from artificial intelligence and data centres.

He declared an “energy emergency” in 2025 to justify moves to keep open ageing coal plants that have been set for closure and exempt ageing coal plants from key air regulations.

He issued a proclamation inviting coal plants to request by e-mail to be exempt from MATS regulations for two years as part of his administration’s energy emergency. Sixty-eight plants were granted exemptions.

Last week, the EPA announced it was repealing the “endangerment finding”, which gave the agency the authority to regulate greenhouse gas emissions, and the White House directed the Pentagon to purchase power from coal plants for military use.

Coal-burning power plants are among the largest sources of hazardous air pollution, including mercury, lead, arsenic and acid gases, as well as major sources of benzene, formaldehyde, dioxins and other organic hazardous air pollutants.

Coal plants generate less than 20 per cent of US electricity, according to the Energy Information Administration. REUTERS