That was pretty much all Congress and a lot of great researchers and journalists throughout the 50s and 60s writing things like Silent Spring that got the general public to a place where they were demanding it. If Nixon hasn't done something to make it look like he'd dealt with the issue we would've likely ended up with something more powerful.

e; I should add though - the world did get a little bit better with Richard Nixon's EPA in it, just not as much better as it could and should have