My experience with the EPA has been that they tend to overreach and, perhaps deliberately (other times due to incompetence), in doing so, let themselves get dragged into court for 10 years where their new rules languish with zero enforcement until the judge rules on the case and usually the EPA is told to start over which resets the clock. I sometimes think the EPA does this on purpose to delay enforcement of any new action.
Then Congress loves to stall, kill and delay enforcement by not funding enforcement.
But if they show up at your door in an unhappy mood, yes, they can be a real pain!!!!