Donald Trump has long talked about reining in the Environmental Protection Agency (EPA), which is in charge of enforcing federal laws on air and water pollution. It’s a top priority for his supporters in the fossil-fuel industry.

But there’s still a lot of uncertainty over what, exactly, this will look like. Trump himself has been all over the map on the agency’s future. In Congress, there are bills floating around that would do everything from abolish the EPA to merely curb its powers at the margins. And, while Trump’s pick to lead the EPA, Scott Pruitt, was an ardent foe of Obama’s environmental policies, he’ll face serious legal hurdles in trying to dismantle them all at once.

So, to simplify things a bit, here are five possible futures for the EPA under Trump, based on what we know so far. As noted, some of these scenarios are way more plausible than others — and they’re not all mutually exclusive. But it’s a way of seeing the options here:

1) The EPA gets abolished altogether

This is the least likely scenario by far, though various politicians have brought it up. At one point during the campaign, Trump expressed interest in eliminating the EPA entirely, though he later backpedaled. And in the House, freshman Rep. Matt Gaetz (R-FL) introduced a bill on February 3 to “terminate” the agency — which has an annual budget of $8 billion and employs more than 15,000 people.

But few of Gaetz’s colleagues are taking his bill seriously, and for good reason. Congress can’t just terminate the EPA and call it a day. There are dozens of sweeping environmental laws that have been enacted since 1970 — including the Clean Air Act and the Clean Water Act — that require the federal government to limit air and water pollution. Those don’t disappear just because everyone at the EPA has been laid off. Congress would either have to give some other agency all of EPA’s responsibilities or repeal America’s bedrock environmental laws. It’d be a nightmare.

Plausibility: This one’s almost certainly not happening.