According to New E.P.A. Plan Could Free Coal Plants to Release More Mercury Into the Air as reported by The New York Times:
In the proposal, the Environmental Protection Agency issued a finding declaring that federal rules imposed on mercury by the Obama administration are too costly to justify.
It drastically changed the formula the government uses in its required cost-benefit analysis of the regulation by taking into account only certain effects that can be measured in dollars, while ignoring or playing down other health benefits.
The result could set a precedent reaching far beyond mercury rules. “It will make it much more difficult for the government to justify environmental regulations in many cases,” said Robert N. Stavins, a professor of environmental economics at Harvard University.
While the proposal technically leaves the mercury restrictions in place, by revising the underlying justifications for them the administration has opened the door for coal mining companies, which have long opposed the rules, to challenge them in court. The rules, issued in 2011, were the first to restrict some of the most hazardous pollutants emitted by coal plants and are considered one of former President Barack Obama’s signature environmental achievements [Jerri-Lynn here: my emphasis.]
Jerri-Lynn here: The rule change – combined with the Trump administration’s other big domestic success – seating federal judges – might well allow courts to overturn environmental and other regulations, even once other personnel in future staff the EPA (see Trump After 500 Days: More Lifetime Federal Judges, which also includes links to other relevant posts). And these Trump judges would also have the power to thwart – at least in the first instance – whatever agenda a more progressive Congress and President might enact to redress the Trump policies.
Source: Another Win for Fossil Fuels: EPA to Weaken Basis for Calculating Mercury and Future Environmental Standards | naked capitalism