The EPA did try to curtail their usage but was blocked by the 5th Circuit[0]. They will hopefully either appeal or try to issue another rule using a different authority.
[0]https://www.reuters.com/legal/litigation/us-appeals-court-cu...
[0]https://www.reuters.com/legal/litigation/us-appeals-court-cu...
That's pretty ridiculous. It would be nice if Congress did the obvious "right thing to do" and amended the law that defines the EPA's power, but we all know that they won't do anything of the kind, and it will be left to a higher court to reinterpret existing law and reverse the decision.