Six months ago, Rocky Mountain Metropolitan Airport Director Paul Anslow didn’t want to talk about leaded fuel. He said he had "zero control" over the airport's use of it. Today, the airport is racing to become the first in Colorado to completely phase the fuel out.
Key things here:
The gas used in the small planes with piston-driven propellers has lead in it. Yeah, the same stuff that was banned from automotive fuel because it causes brain damage in kids.
The FAA has a plan to make going lead-free a requirement by 2031...but right now there isn't anything stopping airport owners (often local governments) from making the switch happen faster. Only thing which might stop this is that the Republican version of the FAA reauthorization bill contains a requirement that airports keep on selling leaded fuel forever, so it's also important to stop that from becoming law.
That's why you should see if your local government can force a phase-out sooner where you live. So far as I am aware, only a couple airports in California and the one in Colorado have done so.