text: Good catch - I just added the other superfund site in Boulder County, Captain Jack Mill.
  
  Tagging could be considered depending on the type of site - landuse=industrial, boundary=protected_area + protect_class=16, could be considered. I'm not sure if anything supports protect_class 16 directly, but the wiki does suggest it applies to superfund sites. Of course the appropriate tagging for what the site originally was (mine, landfill, etc.) is also appropriate.