Add in the consideration that air and water don't respect state boundaries, it would be an even bigger mess. To be fair, the federal government has a history o

Add in the consideration that air and water don't respect state boundaries, it would be an even bigger mess. To be fair, the federal government has a history of abusing the interstate commerce clause -- it's not clear that just because something is capable of crossing a state line, it should automatically fall under federal purview.