This bill helps states have some autonomy from the EPA when dealing with the byproducts of their coal plants. That makes sense: it’s their mess, they should decide how to deal with it. This is some Adulthood 101.
States should be able to deal with their coal ash properly, but so far they haven’t. That’s part of why the Federal government exists: to step in when states can’t get the job done. This bill would give them even more chances to screw up.