Nine states are joining coal company Murray Energy in suing the administration for its proposal to cut carbon pollution from existing power plants.
Murray Energy called the new standards, which are a signature piece of President Obama's climate change legacy, "illegal, irrational, and radical" when first filing the lawsuit June 18.
"EPA’s assertion of authority denied it by Congress imposes real harms on the States now: States have to undertake huge amounts of burdensome work now to develop plans to meet the anticipated rule and cannot wait for the final rule and still have any chance of meeting the indicated deadlines," the brief from the nine states says.
The states take issue with the EPA's "extraordinary" exertion of its authority, according to the brief.
"The “specific prohibition” against the EPA’s proposed rule is in the very statutory provision the agency cites as its authority," the states write in the brief.
The nine states argue that Section 111(d) of the Clean Air Act, under which the EPA is proposing the carbon pollution standards, prohibits the agency from regulating "any air pollutant emitted from a source category that EPA already regulates under" a different section of the law.
That argument is that the EPA can't regulate power plants under Section 111(d) if it already regulates those same power plants under another section of the Clean Air Act.
EPA chief Gina McCarthyGina McCarthyTrump's pick for EPA chief could clean up Obama mess An opportunity to return balance to energy policy Why Trump needs a strong Agriculture secretary MORE has said the agency wouldn't have proposed the rules if they were not legally sound, and stresses that the EPA is affording states as much flexibility as possible on drafting their own plans to reach reduction targets.
The rules, which mandate states cut carbon dioxide emissions from existing power plants 30 percent by 2030, have faced an onslaught of scrutiny from Republicans in Congress.
While Murray Energy's lawsuit is the first brought against the administration's climate regulation, others will likely follow.