There's some commentary out there, including unfortunately from within the EPA itself, suggesting that a Trump administration can't undue much of the nation's environmental regulations, no matter how determined his appointees might be to do so; that things won't be as bad as you fear.
Don't buy it. It's exactly the kind of commentary that said Trump would never be elected in the first place.
This isn't W. This isn't even Reagan. There's no shared world view, or even a rhetorical fig leaf devoted to the need for environmental protection. It's ISIS about to invade and systematically blow-up the nation's environmental safeguards because they don't believe in them. The Clean Air Act is a false idol. The Clean Water Act is blasphemy against an unfettered market. They must be demolished.
Reassurances to the contrary, there are lots of ways to make sure EPA doesn't work. You don't have to repeal the Clean Air Act to make it impotent. As Grover Norquist commented, "I don't want to abolish government. I simply want to reduce it to the size where I can drag it into the bathroom and drown it in the bathtub."
Citizens know in the best of times, it's a chore to make the government enforce what's on the books. Imagine no interest at all in enforcement by EPA, where you still have federal regulations but their implementation is left entirely up to states, cities, or environmental groups. No money for attorneys or staff. All work out-sourced to contractors who are also getting paid by the polluters they're now regulating.
Imagine EPA's scientific panels filled with Michael Honeycutts, the TCEQ's own professional apologist. There's not only no such thing as Climate Change, there's no such thing as smog. Or if there is, it turns out to be good for you!
Over the weekend, reports surfaced of the Trump people literally taking names of EPA employees who've been directly involved in climate change work. He's not even president yet, but he already putting together an environmental enemies list.
Staid observers are counting on bureaucratic inertia to help maintain business-as-usual. But these people are underestimating both the zeal and the intent of the new gang. They're here to destroy, not carry-on. Illusions to the contrary can only facilitate the destruction.