The Mercury and Air Toxics Standards were established in 2012 and updated in 2024, resulting in steep emissions reductions and significant public health benefits for communities across the country. But last year, President Trump exempted 71 coal plants from having to comply with the 2024 rule —and rolling back the rule completely will make the 2012 rule the standard again. This means every coal plant will be complying with a much weaker set of regulations and exempt from regular monitoring and reporting.