https://www.newscientist.com/article/2173680-six-pollution-policies-gutted-by-scott-pruitt-and-what-happens-next/

Over nearly 17 months at the helm, Pruitt oversaw the following actions at the EPA:

These changes are in various places along the spectrum from proposal to implementation, so they could still be altered. But they will have wide effects that may start now, while enforcement of previous rules is on hold.