There have been so many developments recently on the air front (and I’m so far behind due to an appellate brief) that I thought I would combine a few recent items.

First, oral arguments were heard Monday on the challenges to the Bush EPA ozone NAAQS of 0.075 ppb. As I have previously noted, the Court of Appeals for the District of Columbia Circuit has made pretty plain that EPA cannot ignore the recommendations of the Clean Air Science Advisory Committee in setting the NAAQS. Monday’s argument confirmed that view, with Judges Tatel and Griffith both posing tough questions to EPA regarding how it could ignore the CASAC recommendation. Perhaps the most interesting issue to follow will be EPA’s effort to persuade the Court that the CASAC recommendation was not purely based on science, but was also a policy recommendation, on which EPA has the final say. I’m skeptical that the Court will buy that argument.

Second, also on Monday, EPA released a proposal to revise the Mercury and Air Toxics Standards rule for new coal and oil plants.  The revisions include a slight relaxation of the mercury limit from 0.0002 lbs/gigawatt hour to 0.003 lbs/gigawatt hour. EPA does not believe that the change in standard will result in any change in the compliance technology to be utilized. EPA also made revisions to the startup and shutdown provisions. The comment period will run for 30 days from Federal Register promulgation and EPA expects a final rule in March 2013.

Finally, last week, Gina McCarthy announced that it would not be promulgating a rule regulating GHG emissions from existing power plants for several years. (If I were cynical – which I am not – I would note that EPA must really mean it; if they had made the same announcement before the election, many a skeptical eyebrow would have been raised.)