Earlier this week, the “Public Health and Environmental Petitioners” challenging EPA’s decision not to reduce the ozone 
standard below 0.070 ppm filed their “Non-Binding Statement of Issues.” My crystal ball still tells me that the most likely outcome is that the Court of Appeals upholds EPA’s 0.070 ppm standard.
I do think that the Public Health and Environmental Petitioners have a better case than Murray Energy (which filed its Statement of Issues late last year). Given that the Clean Air Science Advisory Committee pretty clearly concluded that there are adverse health impacts below 0.070 ppm, the Public Health and Environmental Petitioners certainly have a credible argument for a lower standard, though I thought EPA did a pretty good job in the final rule insulating itself from challenges on that flank. As to Murray Energy and the other industry and state challengers, I just don’t think that the background argument is going to get them anywhere.